Integrated Copper Nanomaterials‐Decorated Microsphere Photothermal Platform for Comprehensive Melanoma Treatment

Patients who undergo resection for melanoma face challenges, such as delayed healing and radiation dermatitis. Moreover, incomplete tumor resection is a key factor contributing to poor prognosis and increased recurrence rates. However, a therapeutic platform that can effectively prevent tumor recurrence and promote wound healing remains a challenge. Hence, a pioneering approach is presented using melanoma‐derived cancer cell membrane (CM) as a tumor antigen to encapsulate copper (Cu)‐based metal‐organic framework (MOF) nanomaterials to fabricate nanomaterials termed MOF@CM. Then MOF@CM is adsorbed onto polydopamine (PDA)‐modified poly lactic‐co‐glycolic acid (PLGA) porous microspheres (PLGA/PDA) to develop the copper nanomaterials‐decorated microspheres termed PLGA/PDA‐CCM (PLGA/PDA loaded with CM‐coated MOF). It exerts homologous tumor targeting and photothermal effects, inducing immunogenic cell death. Simultaneously, the sustained release of MOF@CM shows enhanced antigen presentation in dendritic cells (DCs) with the help of CpG, and induces DC maturation and activated immune responses, acting as an effective vaccine to prevent tumor recurrence. The platform harnesses the combined advantages of the local thermal effect and the presence of a Cu‐based MOF, which endow antibacterial properties and stimulate angiogenesis, thereby facilitating wound healing and mitigating radiation dermatitis. This integrated microsphere treatment platform represents a promising strategy for addressing melanoma.


Introduction
Malignant skin tumors, including cutaneous melanoma, have a high incidence worldwide, exceeding 1 million cases annually. [1]Current therapeutic approaches for skin tumors include surgery, radiation therapy, and chemotherapy. [2][5] Antibiotics are commonly used to treat bacterial infections, but the growing prevalence of antibiotic resistance poses a challenge. [6,7]Furthermore, radiation dermatitis, a common side effect of radiotherapy characterized by reactive oxygen species (ROS) production and inflammation, significantly affects the quality of life of patients and lacks effective treatment options. [8,9]Nevertheless, developing a therapeutic platform that effectively prevents tumor recurrence and accelerates wound healing is challenging.Hence, the expeditious development of an integration Patients who undergo resection for melanoma face challenges, such as delayed healing and radiation dermatitis.Moreover, incomplete tumor resection is a key factor contributing to poor prognosis and increased recurrence rates.However, a therapeutic platform that can effectively prevent tumor recurrence and promote wound healing remains a challenge.Hence, a pioneering approach is presented using melanoma-derived cancer cell membrane (CM) as a tumor antigen to encapsulate copper (Cu)-based metal-organic framework (MOF) nanomaterials to fabricate nanomaterials termed MOF@CM.Then MOF@CM is adsorbed onto polydopamine (PDA)-modified poly lactic-co-glycolic acid (PLGA) porous microspheres (PLGA/PDA) to develop the copper nanomaterials-decorated microspheres termed PLGA/PDA-CCM (PLGA/PDA loaded with CM-coated MOF).It exerts homologous tumor targeting and photothermal effects, inducing immunogenic cell death.Simultaneously, the sustained release of MOF@CM shows enhanced antigen presentation in dendritic cells (DCs) with the help of CpG, and induces DC maturation and activated immune responses, acting as an effective vaccine to prevent tumor recurrence.The platform harnesses the combined advantages of the local thermal effect and the presence of a Cu-based MOF, which endow antibacterial properties and stimulate angiogenesis, thereby facilitating wound healing and mitigating radiation dermatitis.This integrated microsphere treatment platform represents a promising strategy for addressing melanoma.
strategy is imperative to effectively address the intricate matter of residual cancer cell metastasis, infection control, and wound healing, thereby augmenting the survival rate and quality of life for individuals suffering from skin tumors. [10,11]etal-organic frameworks (MOFs) are crystalline substances consisting of metal ions or metal clusters intricately coordinated with organic ligands.Nanoscale MOFs possess unique properties, such as high surface areas and diverse periodic structures, making them suitable for various applications, including cancer therapy, antibacterial treatment, and wound healing. [12,13]mong copper (Cu)-based MOFs, HKUST-1 (ligand: 1,3,5-benzenetricarboxylic acid, H 3 BTC) has shown promise in cancer treatment due to its redox chemistry, photochemical and photothermal properties, and catalytic activity toward Cu 2þ /Cu þ . [14]dditionally, HKUST-1 has demonstrated angiogenic, antibacterial, and wound-healing effects through the release of Cu 2þ , which has anti-inflammatory effects by modulating immune responses and reducing the release of proinflammatory cytokines. [15]These properties make HKUST-1 a promising candidate for radiation dermatitis treatment.
[18] The premature clearance of HKUST-1 by the mononuclear phagocyte system hampers its accumulation at the target site. [19,20]Although modifications with polymers such as polyethylene glycol (PEG) can enhance the in vivo half-life of nanomaterials, [21,22] the production of antibodies against these polymers can still result in a shortened plasma half-life after repeated doses. [23]To overcome these limitations, cell membrane (CM) camouflage technology has emerged as a promising approach. [19,22,24,25]Membrane-coated nanoparticles possess the merits of natural and synthetic nanomaterials.By incorporating CMs, these nanoparticles can inherit the characteristics of the source cells, offering benefits such as tumor targeting, prolonged circulation time, controlled drug release, reduced toxicity, efficient cellular interaction, and induction of antitumor immune responses.This approach effectively addresses the limitations of nanomaterials, including poor biological stability, inadequate targeting, and rapid clearance. [26,27]Inspiringly, the first-in-class cancer vaccine CE120 (platelet membrane-coated nanomaterial) developed by Cello Therapeutics (China) has received approval from the U.S. Food and Drug Administration (FDA) to conduct its first human clinical trial (Phase I) targeting various solid tumors. [28]Tumor CM-coated nanomaterials have demonstrated great potential for preserving a wide range of tumor antigens, making them suitable for cancer vaccines to prevent tumor recurrence. [29]Furthermore, there are immune escape molecules on the surface of the tumor CM, so nanomaterials wrapped within the tumor CM can evade immune clearance, thus prolonging the circulation time of nanomaterials and enhancing their accumulation at the tumor site. [17,30]dditionally, tumor CM-coated nanomaterials can exhibit improved uptake by homotypic tumor cells. [31,32]Therefore, tumor CM-coated nanomaterials provide a promising solution for improving the efficacy and safety of nanomaterials because they solve the problems of short half-lives and lack of tumor targeting.However, while Cu 2þ can stimulate tissue regeneration by promoting cell proliferation, differentiation, and angiogenesis, the excessive accumulation of Cu ions can lead to cell death and Cu toxicity. [33,34]Therefore, the development of approaches to control the release of Cu 2þ from HKUST-1 is crucial for preventing potential cytotoxic effects.
The use of injectable porous microspheres as carriers for medical materials, drugs, and cytokines has been suggested as an attractive option for sustained release, thus representing a promising approach for realizing rapid HKUST-1 degradation and controlled release in vivo [35][36][37] and avoiding Cu 2þ toxicity and enhancing tissue regeneration.PLGA, a biodegradable copolymer approved by the FDA, can be used as a raw material for porous microspheres. [38,39]In addition to its stabilityenhancing properties, porous PLGA microspheres exhibit remarkable load efficiency due to their high specific surface area.To further improve drug bioavailability and therapeutic efficacy, PLGA can be modified with dopamine, allowing for excellent maneuverability during crosslinking, as the catechol groups can form covalent or noncovalent bonds that provide rapid and robust adhesion. [40,41]Moreover, catechol groups can easily be oxidized to neutralize ROS, promote antioxidant enzyme activities, and enhance tissue regeneration. [42]Importantly, due to the redox activity of dopamine under alkaline conditions, it can spontaneously form a polydopamine coating on the surface of PLGA, which endows the microspheres with photothermal properties. [43]hus, the objective of this study was to create a multifunctional nanoplatform for the eradication of skin tumors, prevention of recurrence, and postoperative wound management.This was achieved through the camouflage of HKUST-1 MOF coated with a tumor CM (MOF@CM) and the incorporation of porous PLGA microspheres modified with PDA.The resulting sustained-release platform was termed PLGA/PDA-CCM (PLGA/PDA loaded with CM-coated MOF), which effectively combines the multiple functions of sustained microsphere release, photothermal tumor killing, CM camouflage technology, and Cu-MOF (Scheme 1A,B).PLGA/PDA-CCM demonstrates robust photothermal activity and sustained release as well as antibacterial and antioxidant effects.The tumor-targeting ability of MOF@CM, combined with the controlled release capability of PLGA/PDA, facilitates active accumulation at tumor sites and gradual release in healthy tissue.Upon laser radiation, photothermal therapy (PTT) effectively induces in situ tumor eradication.Additionally, dendritic cells' (DCs) uptake tumor CMs, presenting processed tumor antigens to activated T cells.During wound healing, the slow release of Cu 2þ from HKUST-1 stimulates angiogenesis, while the combination of PDA and HKUST-1 enhances the photothermal activity, antibacterial effects, and antioxidative effects of the material.This leads to the promotion of wound healing and the alleviation of radiation dermatitis by stimulating angiogenesis, antioxidation, and inflammation (Scheme 1C).The versatility of PLGA/PDA-CCM makes it an ideal treatment platform for postoperative recovery of skin tumors, enabling tumor treatment, recurrence prevention, wound healing, and radiation dermatitis.This innovative approach integrates the effects of eliminating tumors, preventing recurrence, and promoting wound healing, offering a promising therapeutic tool for managing postoperative complications following tumor surgery and providing a comprehensive strategy for treating melanoma and associated complications.

Preparation and Characterization of the Nanomaterials
HKUST-1 cells were coated with a tumor CM and cholesterolmodified CpG to prepare MOF@CM (a MOF coated with a CM), as depicted in Figure 1A.X-ray diffraction (XRD) analysis of the crystal phase of HKUST-1 revealed a cubic crystal structure with an average crystal parameter of 26.20 Å (Figure 1B), which was consistent with the crystal structure reported in the literature. [44,45]The diffraction peaks at 2θ = 8.34°, 16.68°, 17.38°, and 25.20°represented crystal plane spacings of (200), (400), (100), and (600), respectively.These XRD results confirmed the successful crystal formation of HKUST-1.Furthermore, X-ray photoelectron spectroscopy (XPS) showed that HKUST-1 contains three elements, Cu, C, and O. Cu 2þ serves as the central metal, whereas H 3 BTC (1,3,5-Trimesic Acid) acts as the ligand skeleton.The Cu 2p and Cu LM2 spectra indicated that the electron binding energies of 953.98, 934.18, and 570.48 eV corresponded to Cu 2p1/2, Cu 2p3/2, and Cu LM2, respectively, which is consistent with the literature. [46]The binding energy at 934.18 eV indicated the presence of Cu 2þ , along with "shake-up satellite bands" (962.78,939.58 eV) [47] (Figure 1C).The C 1 s and O 1 s spectra showed electron binding energies of 288.58 eV, corresponding to aromatic C (C─C); 284.78 eV, corresponding to carboxylic acid C (─COOH); and 531.28 eV, Scheme 1. Preparation and characteristics of PLGA/PDA-CCM for treatment.A) HKUST-1 is produced by a simple stirring method at room temperature.B) The PLGA-MS was modified with polydopamine, and then adsorbed B16F10 cell membrane biomimetic nanoparticles MOF@CM.PLGA/PDA-CCM provides a variety of functions for tumor therapy, radiation dermstitis management and wound healing.C) PLGA/PDA-CCM can directly induce tumor ablation under NIR irradiation.Additionally, ICD-associated DAMPs and tumor CMs are absorbed and presented by DCs to activate T cells.The appropriate heat and released HKUST-1 have antibacterial, anti-inflammatory, and angiogenesis-stimulating effects, promoting the healing of radiation dermatitis and wounds.(PLGA-MS: poly lactic-co-glycolic acid (PLGA) porous microsphere; PLGA/PDA: polydopamine (PDA)-modified PLGA-MS; MOF@CM: B16F10 CM-coated MOF; PLGA/PDA-CCM: PLGA/PDA loaded with MOF@CM).
Figure 1.Synthesis and characterization of nanomaterials.A) Schematic illustration of the MOF@CM synthesis method.B) XRD spectrum of HKUST-1, the MOF used in the synthesis of MOF@CM.C) XPS spectra of HKUST-1 in different binding energy ranges, confirming the presence of copper, carbon, and oxygen.D) Zeta potentials of the MOF and MOF@CM, indicating the surface charge of the nanomaterials.E) Particle size distributions of the MOF and MOF@CM.F) TEM images and elemental mapping of HKUST-1 and MOF@CM, confirming the successful coating of the CM onto the MOF.The structure of the CM is depicted with a red line indicating its boundaries.G) SDS-PAGE analysis of whole cells, the CM, and MOF@CM demonstrating the presence of CM proteins in the coated MOF particles.H) Fluorescence images of B16F10 and CT26 cells incubated with DiD-labeled MOF@CM showing the cellular uptake of the particles.Red fluorescence represents DiD-labeled MOF@CM, while blue fluorescence represents DAPI-stained cell nuclei.I) Flow cytometry detection of B16F10 and CT26 cells incubated with DiD-labeled MOF@CM, which was used to quantify the cellular uptake of the particles.The data are presented as the mean AE standard deviation (SD) (n = 3).***P < 0.001.corresponding to carboxylic acid O (O─C═O) (Figure S1, Supporting Information).These XPS results confirmed the successful construction of the metal Cu-organic coordination compound HKUST-1 to ensure the sustained release of Cu 2þ .
Dynamic light scattering analysis indicated that the size of MOF@CM was marginally greater than that of HKUST-1 (141.7 AE 2.8 nm vs. 113.9AE 1.0 nm) (Figure 1D).The surface potential of MOF@CM was À26.17 AE 0.96 mV, whereas that of the unmodified MOF was À9.88 AE 2.15 mV (Figure 1E), confirming the presence of a negatively charged CM coating on the MOF@CM surface.Transmission electron microscopy (TEM) images exhibited clear changes before and after CM encapsulation, with a clear core-shell structure observed around the MOF@CM (Figure 1F).The results of elemental mapping analysis confirmed the incorporation of S and P in MOF@CM, while HKUST-1 almost did not contain these two elements, confirming the successful coating of the MOF on the CM (Figure S2, Supporting Information).
To verify that the proteins present in the CM were extracted from tumor cells and that MOF@CM retained most of the proteins in tumor cells, including tumor-associated antigens, we conducted sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) for protein spectrum comparison.The protein profiles of the extracted CM and MOF@CM were highly consistent with those of the whole cell, suggesting that the proteins distinctive from those of B16F10 cells were effectively preserved within the CM (Figure 1G).Confocal laser scanning microscopy showed that B16F10 cells were more likely to engulf the red fluorescent probe (DiD)-labeled MOF@CM (DiD-MOF@CM) than were CT26 cells.The red fluorescence intensity in CT26 cells was lower than that in B16F10 cells (Figure 1H).Flow cytometric analysis of B16F10 cells revealed that the percentage of endocytosis-positive DiD-MOF@CM cells (80.77AE 0.85%) was significantly greater than that of CT26 cells (25.32 AE 6.44%) (P < 0.001) (Figure 1I,J).Moreover, the intracellular Cu-ion concentration did not increase in CT26 cells after MOF@CM treatment (0.76 AE 0.26 vs. 0.99 AE 0.05 μM 10 À3 cells before vs. after treatment), whereas B16F10 cells exhibited greater uptake of Cu ions after MOF@CM treatment (0.59 AE 0.11 vs. 2.61 AE 0.46 μM 10 À3 cells, P < 0.001) (Figure S3, Supporting Information).Taken together, these studies confirmed the successful formation of MOF@CM, which possessed homologous targeting ability in homotypic cancer cells.

Preparation and Characterization of Microspheres
PLGA porous microspheres (PLGA-MS) were prepared by the gelatin-based porogen approach and modified with dopamine to form polydopamine-modified porous PLGA microspheres (PLGA/PDA).MOF@CM was then adsorbed to PLGA/PDA to obtain the resulting sustained-release platform termed PLGA/PDA-CCM (PLGA/PDA loaded with CM-coated MOF).(Figure 2A).The modified microspheres were black in color due to the self-polymerization of dopamine, which formed a PDA adhesion layer (Figure 2B).Microscopic analysis revealed that the particle size of the PLGA-MS was mainly distributed between ≈200 and 350 μm, with no significant change in particle size after dopamine modification (Figure 2C).Scanning electron microscopy (SEM) showed that the microspheres had a spherical porous structure with interconnected holes measuring a few micrometers to dozens of micrometers in diameter (Figure 2D).The morphology of the microspheres remained largely unchanged after dopamine modification, with numerous holes present on the surface and in the interior space.Elemental mapping indicated an increase in N content upon dopamine modification, although the total amount of N remained relatively low (Figure S4, Supporting Information).XPS confirmed the successful modification of dopamine on the surface of the PLGA/PDA microspheres, as evidenced by the presence of N (Figure 2E).Fourier transform infrared (FTIR) spectroscopy revealed a wide absorption band corresponding to dopamine at 1500-600 cm À1 , with characteristic absorption bands related to the phenol structure at 3350 cm À1 (aromatic O─H stretching vibration) and 1620 cm À1 (aromatic C═C stretching vibration).The influence of the N─H stretching vibration was also observed in the spectrum due to the presence of dopamine. [48]The infrared spectrum of PLGA/PDA exhibited a characteristic peak band between 1620 and 1750 cm À1 , as well as a new absorption band at 1516 cm À1 , which could be attributed to the stretching vibration of the double bond in the benzene ring skeleton of the PDA modification layer.This is supported by the presence of a similar frequency band caused by N─H shear vibration in the PDA spectrum (Figure 2F).
We then proceeded to investigate the loading efficiency and release profile of MOF@CM in PLGA-MS and PLGA/PDA.As shown in Figure 2G, with the extension of time, the adsorption rates of MOF@CM on PLGA/PDA and PLGA-MS increased gradually.At 5 h, both adsorption rates reached their peak, and the adsorption rate of PLGA/PDA was significantly greater than that of PLGA-MS (29.00 AE 1.81 μg mg À1 vs. 38.54AE 2.95 μg mg À1 , P < 0.01).In vitro release studies revealed the cumulative release of PLGA/PDA and PLGA-MS after 21 days, and the total release of these materials from PLGA/PDA was significantly greater than that from PLGA-MS on day 21 (P < 0.01) (Figure 2H).In addition, we employed a copper-ion detection kit to assess the release of copper (Figure S5, Supporting Information).PLGA/PDA coated with MOF@CM exhibited a total release of 0.34 AE 0.02 μg of Cu within 24 h, slightly higher than PLGA-MS (0.26 AE 0.04 μg).After 21 days, a greater amount of MOF@CM was adsorbed onto PLGA/PDA, resulting in a higher release of Cu (P < 0.001).Subsequently, DiD-stained MOF@CM was separately adsorbed onto PLGA-MS and PLGA/PDA, and the adsorption of MOF@CM was visualized using confocal microscopy (Figure S6, Supporting Information).The images reveal the presence of red fluorescence of DiD surrounding the microspheres, indicating the successful adsorption of MOF@CM onto the surfaces of PLGA-MS and PLGA/PDA.Due to the presence of polydopamine on the surface of PLGA/PDA, a greater amount of MOF@CM can be adsorbed.SEM analysis revealed that the microspheres underwent gradual degradation over time, resulting in gradual morphological deformation and a decrease in size (Figure 2I).
Compared with solid microspheres, porous microspheres offer a greater specific surface area, facilitating the surface attachment and delivery of a large quantity of nanomaterials, cells, and other cargos. [35]A range of porogen agents, such as ammonium bicarbonate, have been used for the production of porous microspheres.However, previous studies and our preliminary results showed that the ammonium bicarbonate foaming method frequently results in irregular pores and lacks the ability to control porosity effectively. [49]In contrast, the use of gelatin as a porogen guarantees the stability and uniformity of pore formation.Consequently, in this study, gelatin was utilized as a porosity control agent, with the objective of addressing the limitations associated with the use of ammonium bicarbonate.[52] Bio-derived PDA possesses abundant functional groups, such as catechol, carboxyl, and amino groups, that enable satisfactory adhesion properties through Schiff base and Michael reactions. [40,41,53][56] Our findings showed that modifying the microspheres with PDA increased the efficiency of loading MOF@CM and reduced its burst release, resulting in prolonged release over an extended period."PDA-coated microspheres" offer a versatile method for achieving a high payload capacity and sustained release of nanomaterials within microspheres.

Photothermal Properties
PDA is an ideal photothermal agent due to its near-infrared (NIR) absorption at 808 nm and high photothermal conversion efficiency. [56]The photothermal properties of MOF@CM, PLGA/PDA, and PLGA/PDA-CCM were studied using an infrared camera.After 300 s of laser irradiation, MOF@CM showed only a slight increase in temperature (30.0 °C), whereas the temperatures of PLGA/PDA and PLGA/PDA-CCM increased significantly to 55.7 and 56.7 °C, respectively, demonstrating the excellent photothermal conversion ability of the PDA-coated microspheres (Figure 3A,D).Furthermore, after three cycles of NIR laser irradiation, the temperature of the PLGA/PDA-CCM increased in a concentration-dependent manner (Figure 3B), and robust photothermal conversion and minimal loss of thermal fatigue resistance were observed, indicating the excellent photothermal conversion ability and photostability of the resulting material (Figure 3C).
Bacterial infection is one of the most important causes of delayed wound healing, and materials applied after the resection of skin tumors should have antibacterial effects. [57,58]hotothermal materials have been used for antibacterial therapy due to their ability to photothermally ablate bacteria. [59,60]To evaluate the antibacterial properties of PLGA/PDA-CCM in vitro, we used two of the most common pathogens, E. coli and S. aureus, which are Gram-negative and Gram-positive bacteria, respectively.In colony formation assays under conditions devoid of NIR irradiation, the bacterial viability of E. coli in the MOF@CM, PLGA/PDA, and PLGA/PDA-CCM groups was 51.67 AE 15.85%, 90.89 AE 4.93%, and 72.58 AE 1.66%, respectively (Figure 3E and S7, Supporting Information), and that of S. aureus was 28.09 AE 8.33%, 90.63% AE 2.10%, and 51.24% AE 11.42%, respectively (Figure S8A, Supporting Information), indicating their weak antibacterial ability in the absence of NIR irradiation.Following NIR irradiation, the bacterial viability of E. coli in the PLGA/PDA and PLGA/PDA-CCM groups was significantly reduced, decreasing to 20.93% AE 3.60% and 1.16% AE 1.05%, respectively (Figure S7, Supporting Information), and the bacterial viability of S. aureus in the PLGA/PDA and PLGA/PDA-CCM groups was 12.59% AE 2.54% and 6.73% AE 5.83%, respectively (Figure S8B, Supporting Information).These findings illustrate that both PLGA/PDA and PLGA/PDA-CCM can effectively inhibit S. aureus and E. coli when subjected to NIR irradiation, while NIR irradiation did not promote the antibacterial activity of MOF@CM.Under photothermal conditions, PLGA/PDA-CCM showed better bacterial inhibition of E. coli than did PLGA/PDA (PLGA/PDA: 20.93% AE 3.60%, PLGA/PDA-CCM: 1.16% AE 1.05%, P < 0.001).Similar results were found for S. aureus.To evaluate the effects of PLGA/PDA-CCM on bacteria more intuitively, changes in bacterial morphology and integrity after exposure to PLGA/PDA-CCM were observed through SEM (Figure 3F and S8C, Supporting Information).In the absence of NIR irradiation, the bacterial surfaces of S. aureus and E. coli treated with PLGA/PDA-CCM exhibited slight wrinkles.This shrinkage can be attributed to the action of the Cu ions present in the MOF, which damages the bacterial membrane surface, disrupts normal enzymatic function, and induces oxidative stress. [61,62]In contrast, upon laser irradiation of PLGA/PDA-CCM, both E. coli and S. aureus exhibited severe deformation and damage.These results provide compelling evidence for the efficacy of PTT as an enhanced antibacterial approach.
The photothermal activity of the materials in vitro was assessed by live/dead staining and CCK8 assays.As expected, few dead cells were observed in the absence of NIR (Figure 3G).Under NIR irradiation, although MOF@CM exhibited weak toxicity, the PLGA/PDA and PLGA/PDA-CCM groups exhibited potent photothermal anticancer effects.Consistent results were obtained with the CCK-8 assays (Figure 3H).Cell viability after treatment with 2 mg mL À1 PLGA/PDA-CCM, PLGA/PDA, or MOF@CM was 96.71% AE 2.87%, 92.14 AE 8.51%, and 95.22% AE 1.12%, respectively, indicating good biocompatibility.In the presence of NIR irradiation, the cytotoxicity of PLGA/PDA-CCM significantly increased in a dose-dependent manner.At 1 mg mL À1 , the cell survival rate decreased to 29.67% AE 1.68%, whereas the cell viability in the PLGA/PDA and MOF@CM groups was 25.06 AE 2.56% and 76.30 AE 4.09%, respectively.These findings indicate that both PLGA/PDA-CCM and PLGA/PDA exhibited potent cytotoxicity under NIR irradiation, whereas the MOF@CM group exhibited weak photothermal efficacy.

Cellular Proliferation, Migration, and Tube Formation
To investigate the potential of PLGA/PDA-CCM to promote wound healing, we evaluated the effects of different materials on NIH-3t3 cell migration and angiogenesis in vascular endothelial cells.Cytotoxicity assays of NIH-3t3 cells revealed that MOF@CM at concentrations less than 50 μg mL À1 had low toxicity (Figure S9, Supporting Information).PLGA/PDA and PLGA/PDA-CCM showed almost no toxicity to cells even at the highest concentration of 3 mg mL À1 , indicating good compatibility of the microspheres.Therefore, the dose of MOF used in our study did not exceed 50 μg mL À1 .Flow cytometric analysis of apoptosis also indicated that MOF@CM resulted in a minimal proportion of apoptotic NIH-3t3 cells (2.68 AE 0.17%) (Figure S10, Supporting Information).The proportion of apoptotic cells in the PLGA/PDA-CCM group (1.73 AE 0.17%, P < 0.001) was even lower than that in the MOF@CM group.Additionally, PLGA/PDA did not cause any discernible toxicity, indicating the high compatibility of the microspheres.These findings suggest that while Cu ions may have slight toxicity toward cells, the sustained release of Cu ions from PLGA/PDA microspheres can effectively mitigate their toxicity.
[67] It has been reported that CuSO 4 can induce the expression of growth factors, thereby promoting the migration of keratinocytes and fibroblasts. [68]To assess the impact of various materials on cell migration, a scratch wound healing assay was conducted using NIH3T3 cells and diverse materials (Cu concentration = 2 Â 10 À6 M), [66] with CuSO 4 serving as a positive control (Figure 4A,D).After 24 h, 41.52 AE 7.69% of the CuSO 4 and MOF@CM groups (P < 0.01, vs. control) died, and 40.12 AE 5.044% (P < 0.05, vs. control) of the plants died, indicating that MOF and CuSO 4 could promote cell migration.No significant difference was observed in the migration rate of cells between the PLGA/PDA group and the control group (21.28 AE 7.35% vs. 16.65 AE 3.13%), indicating that the microspheres themselves did not promote cell migration.In contrast, the migration rate of cells in the PLGA/PDA-CCM group (46.49AE 9.02%, P < 0.01) was significantly greater than that in the control group and was comparable to that in the MOF@CM group.Similar results were obtained using a Transwell chamber migration assay (Figure 4B,E).The PLGA/ PDA scaffold did not promote cellular migration, whereas the number of migrated cells in the CuSO 4 and MOF@CM groups was similar and significantly greater than that in the control group (P < 0.0001), indicating that microsphere loading did not affect the effects of MOF@CM on cell migration.Cu ions can promote angiogenesis by inducing the expression of growth factors. [69]The PLGA/PDA combination did not affect the number of cell network nodes, whereas the number of cell network nodes in the PLGA/PDA-CCM and MOF@CM groups was similar to or significantly greater than that in the control group (P < 0.05), indicating that microsphere loading did not affect the effect of MOF@CM on angiogenesis (Figure 4C,F).
Our findings demonstrated that both Cu-MOF and PLGA/ PDA-CCM can effectively enhance cell migration and angiogenesis.The presence of Cu ions in these materials, even at low concentrations, is likely responsible for their angiogenic effects. [65,70]his finding is in line with previous studies that have reported similar outcomes with Cu ions. [70]However, high concentrations of copper ions may be toxic, and these ions can adversely affect proteins, thereby affecting cell migration and other functions. [66]otably, cells in the MOF@CM and CuSO 4 groups exhibited comparable cell mobility, whereas the PLGA/PDA-CCM group displayed the highest cell mobility, potentially attributed to the slow release of Cu ions, which mitigated cytotoxicity and apoptosis.While the slight toxicity of Cu ions may contribute to apoptosis, our sustained-release microsphere strategy effectively mitigated these side effects while still promoting cell migration.Our sustained-release microsphere strategy provides a universal approach to effectively preserve the proliferative activity of copper ions while simultaneously reducing their potential toxicity.This controlled release mechanism ensures balanced and sustained delivery of copper ions, enabling their beneficial effects on cell migration and angiogenesis while minimizing adverse effects.Therefore, our findings underscore the innovative potential of PLGA/PDA-CCM as a promising platform for enhancing cell migration and angiogenesis in the context of skin healing, offering valuable insights for the development of advanced wound healing materials.

Immunostimulatory Assays
To investigate the potential of these nanomaterials to initiate tumor immunity, we explored the ability of PLGA/PDA-CCM to facilitate antigen presentation to DCs and promote DC maturation.Our aim was to assess the effectiveness of nanomaterials in enhancing the presentation of major histocompatibility complex-I (MHC-I) antigen peptides by DCs.To achieve this goal, we extracted CMs containing ovalbumin (OVA) from OVA-B16F10 cells and prepared OVA-MOF@CM.We then assessed the ability of OVA-MOF@CM to promote antigen cross-presentation in DCs (Figure 4H and S11, Supporting Information).The OVA group exhibited a positive H-2 kb/ SIINFEKL staining rate of 4.52 AE 0.58%.When DCs were incubated with OVA-MOF@CM, the percentage of positive cells significantly increased to 6.75 AE 0.76% (P < 0.01), suggesting that OVA-MOF@CM could effectively enhance the antigen cross-presentation of OVA.Furthermore, microsphere loading did not affect the antigen presentation ability of OVA-MOF@CM, as reflected by the comparable percentage of OVA-MOF@CM-and PLGA/PDA-CCM-OVA-treated cells (6.75 AE 0.76% vs 8.13 AE 1.38%).In fact, the total amount of OVA-MOF@CM released by PLGA/PDA-CCM-OVA within 24 h was lower than that in the OVA-MOF@CM group, whereas their antigen-crosslinking ability remained comparable, suggesting that the sustained release of MOF@CM from PLGA/PDA could promote antigen cross-presentation in DCs.
The capacity of these nanomaterials to stimulate the maturation of bone marrow-derived DCs (BMDCs) was also investigated.The expression of CD86 and CD80 was analyzed in BMDCs after treatment for 24 h.(Figure 4G).The proportion of CD80þCD86þ cells in the control group was 4.84 AE 1.16%, and the addition of B16F10 CM significantly increased this proportion to 22.4 AE 3.61% (P < 0.0001) (Figure 4I).Notably, compared with those in the CM group, the proportion of MOF@CM-positive cells in the CM group was significantly greater (P < 0.0001), suggesting that the nanomaterials encapsulated in the CM were more readily endocytosed by BMDCs, thereby inducing their maturation in vitro.Similarly, compared with MOF@CM, PLGA/PDA-CCM also had a comparable proportion of positive cells.Additionally, we analyzed the secretion of the immune cytokines TNF-α and IL-6 by BMDCs and obtained similar results (Figure 4J,K).Compared with control BMDCs, MOF@CM-and PLGA/PDA-CCM-treated BMDCs showed significantly increased expression of TNF-α and IL-6 (P < 0.0001).
The results demonstrated that MOF@CM can effectively induce the maturation of DCs and enhance their antigenpresenting capabilities.Furthermore, the incorporation of nanomaterials within the CM facilitates their uptake by DCs, resulting in increased maturation.In contrast, the ability of nanomaterials to induce DC maturation remains similar when loaded with microspheres.73] These findings further support the idea that nanomaterials could promote antigen presentation and DC maturation. [18,25,74]herefore, these findings emphasize that MOF@CM can promote antigen presentation and DC maturation, while its sustained release from microspheres does not affect these processes.

In Vivo Distribution
To assess the tissue distribution of the nanomaterials, we examined the distribution of DiD-labeled MOF@CM and PLGA/PDA-CCM in a B16F10 tumor-bearing mouse model (Figure S12, Supporting Information).The cumulative fluorescence intensity within the tumors treated with both DiD-labeled MOF@CM and PLGA/PDA-CCM gradually decreased over time, indicating gradual penetration of the nanomaterials outside the tumor.Notably, the fluorescence intensity of DiD-PLGA/PDA-CCM was greater than that of DiD-labeled MOF@CM.Semiquantitative analysis revealed that after 48 hours, the fluorescence intensity in the MOF@CM group decreased by ≈72%, while that in the PLGA/PDA-CCM group decreased by only 48%.These results suggest that the sustained release of MOF@CM from microspheres may impede their clearance from tumors, potentially enhancing their tumor-targeting capabilities and immune response activation.

In Vivo Antitumor Assays
To investigate the potential of nanomaterials for PTT to inhibit tumor growth, we conducted an experiment in which C57BL/6 mice-bearing B16F10 melanoma were used (Figure 5A).The final tumor weights and tumor growth curves of the mice were measured (Figure 5B-D and S13A, Supporting Information).Compared with those in the control group, MOF@CMþDark, MOF@CMþLight, PLGA/PDAþLight, PLGA/PDA-CCMþDark, and PLGA/PDA-CCMþLight effectively suppressed tumor growth, and the tumor inhibition rates were 35.09%, 39.20%, 38.50%, 52.56%, and 68.77%, respectively.PLGA/PDA-CCMþLight had the optimal antitumor efficacy.During the treatment, the body weights of the mice in each group remained within the normal range (Figure S13B, Supporting Information).
Histological assays for biocompatibility and biosafety were also conducted on the nanomaterials (Figure S14, Supporting Information).Hematoxylin and eosin (H&E) staining revealed no obvious toxicity to the primary organs (lung, kidney, heart, spleen, or liver), indicating that all the treatments were safe.Tumor tissues obtained from mice were also subjected to H&E, Ki-67, and HMGB1 staining (Figure 5E).Staining revealed robust cell proliferation in the control group, whereas many tumor cells treated with PLGA/PDA-CCMþLight were extensively lysed, with massive tumor necrosis and low expression of Ki67.Additionally, HMGB1 immunofluorescence staining showed that the PLGA/PDAþLight and PLGA/PDA-CCMþLight treatments effectively induced the release of HMGB1, suggesting the induction of ICD.
To explore the mechanisms underlying the antitumor efficacy of PLGA/PDA-CCM, we analyzed immune profiles in tumordraining lymph nodes (TDLNs) and the tumor microenvironment (TME).[77] We found that PLGA/PDA-CCM treatment significantly promoted the maturation of DCs, especially under NIR irradiation (Figure 6A).The maturation rate of DCs was greater in the PLGA/PDA-CCMþLight group (36.4 AE 1.44%) than in the PLGA/PDA-CCM (18.51 AE 1.50%), PLGA/PDAþL (26.81 AE 1.96%), and MOF@CMþL groups (13.55 AE 1.16%) (P < 0.0001), indicating that NIR irradiation, MOF@CM, and microsphere loading were critical for inducing DC maturation.In the TME, immune cells play a pivotal role in tumor progression, and the presence of an immunosuppressive TME can negatively impact the effectiveness of immunotherapy. [78]As depicted in Figure 6C,D, the CD8þ T-cell infiltration rate was greater in the PLGA/PDA-CCMþLight group (18.49AE 1.42%) than in the PLGA/PDA-CCM (11.20 AE 0.69%), PLGA/PDAþLight (11.90 AE 1.80%), and MOF@CMþL groups (10.67 AE 0.31%) (P < 0.0001).Similar results were obtained for CD4þ T-cell infiltration (Figure S15, Supporting Information).Regulatory T cells (Tregs) expressing Foxp3 in the TME prevent the function of cytotoxic T lymphocytes (CTLs) and limit the infiltration of CTLs in the TME through various pathways; therefore, the ratio of CTLs/Tregs is very important for the TME. [79,80]Figure 6E,F shows that PLGA/PDA-CCMþLight had the highest CTL/Treg ratio, suggesting that it could reduce the frequency of immunosuppressive Tregs, increase the abundance of CD8þ T cells, and effectively reverse the immunosuppressive TME.
Taken together, these findings indicate that PLGA/PDA-CCM not only facilitates antigen cross-presentation but also triggers DC maturation, thereby enhancing T-cell-mediated tumor cell killing.Additionally, PTT using PLGA/PDA-CCM and light induces ICD, offering another approach for dual activation of tumor immunity.This strategy promotes the nanomaterialmediated endocytosis of tumor CM antigens by DCs, leading to enhanced antigen presentation, DC maturation, and activation of immune responses.Furthermore, tumor-targeting PTT achieves precise tumor killing effects and induces the release of ICD markers, further activating DCs and T cells to eliminate  tumor cells.Previously, only one or two effects (i.e., homologous targeting or DC maturation) of tumor CM-coated nanomaterials were discussed. [81,82]The idea of "tumor CM-coated nanomaterial-derived four efficacy" may provide a general strategy to realize homologous targeting, PTT, enhanced antigen presentation, and DC maturation.Significantly, the microspheres not only enhance photothermal activity but also contribute to the sustained release of nanomaterials, thereby augmenting long-term immune activation.

Therapeutic Effect on Distal Tumors
After tumor resection, residual tumor cells or metastatic cells may still form distal recurrent tumors in other parts of the body. [83]Therefore, we aimed to evaluate the distal antitumor immune efficacy of these nanomaterials using a bilateral subcutaneous tumor model.An illustration of the experimental schedule is shown in Figure 7A.The final primary tumor weights and tumor growth curves of the mice were measured (Figure 7B-D).Compared with those in the control group, MOF@CMþDark, MOF@CMþLight, PLGA/PDAþLight, PLGA/PDA-CCMþDark, and PLGA/PDA-CCMþLight effectively suppressed tumor growth, and the tumor inhibition rates were 35.58%, 39.92%, 38.00%, 67.60%, and 71.09%, respectively.PLGA/PDA-CCMþLight had the optimal antitumor efficacy.Similar results were obtained in the distant tumor growth assay (Figure 7E-G).Additionally, H&E staining revealed that the control group, light group, and PDA/PLGA group exhibited prominent nuclear polymorphisms and cell proliferation, while the MOF@CM, MOF@CMþLight, PLGA/PDAþLight, PLGA/PDA-CCM, and PLGA/PDA-CCMþLight groups exhibited varying degrees of cell swelling and nuclear condensation (Figure 7H).Moreover, immunofluorescence staining to evaluate T-cell infiltration revealed an increase in the red fluorescence signal of CD4þ T cells in tumors treated with PLGA/PDA-CCM, along with elevated infiltration of CD8þ T cells.Notably, the highest fluorescence ratio was observed in the PLGA/PDA-CCMþLight group.These findings indicate that the implementation of PLGA/PDA-CCMþLight therapy effectively augmented the infiltration of CTLs (Figure 7H).In the distant tumors, flow cytometry analysis demonstrated that the proportion of CD8þ T cells in the MOF@CM treatment group was significantly greater than that in the control group (MOF@CM: 4.74 AE 0.37%; MOF@CMþLight: 4.88 AE 0.40%, P < 0.001, vs. the control group) (Figure 7I,J).Compared with that of PLGA/PDA, the proportion of CD8þ T cells was greater in the PLGA/PDAþLight group (4.93 AE 0.7%, P < 0.001).Notably, the PLGA/PDA-CCMþL group exhibited the highest proportion of CD8þ T cells (7.52 AE 0.32%).Similar results were observed for CD4þ T cells (Figure S16, Supporting Information).
While primary tumors can be surgically removed, the persistence of distant metastatic lesions often leads to tumor recurrence. [84]The elimination of distant metastatic lesions significantly improves the survival rate of patients following tumor surgery.Our experiments targeting contralateral tumors demonstrated that PLGA/PDA-CCMþLight effectively inhibited the growth of contralateral tumors by promoting DC and T-cell infiltration.These findings highlight that PLGA/PDA-CCMþLight not only eliminates primary tumor lesions but also targets distant lesions, demonstrating its potential in combating tumor metastasis and recurrence.The mechanism by which PLGA/PDA-CCMþLight targets distant tumors may involve the induction of ICD following photothermal ablation of the primary tumor, and this process activates the tumor immune response, ultimately leading to the eradication of distant metastatic lesions. [63,85,86]6.3.In Vivo Healing Effect on Infected Wounds In vivo assessment of the antibacterial and wound healing efficacy of the nanomaterials was carried out in a whole-skin wound infection model in mice using S. aureus (Figure 8A).Over time, the wound area decreased in all groups of mice.On day 3 postsurgery, most groups exhibited varying degrees of bacterial infection, with some groups showing larger wound areas than on day 0 (Figure 8B).After 7 days, compared with the NIR irradiation treatment alone, the MOF@CMþLight treatment accelerated wound healing (wound closure rate: 62.16 AE 5.66% vs 37.29 AE 7.96%, P < 0.01).Notably, the PLGA/PDA-CCMþLight treatment had the best wound closure rate (79.13 AE 7.07%), which was greater than that of the PLGA/PDA-CCM, PLGA/ PDAþLight, and MOF@CMþLight treatments.On day 14, the PLGA/PDA-CCMþLight treatment also had the highest wound closure rate (99.43 AE 0.60%), which differed substantially from that of the PLGA/PDA (78.73 AE 1.16%) (P < 0.01) and light groups (91.50 AE 1.15%), indicating that PLGA/PDA-CCM and NIR irradiation synergistically accelerated wound healing.Taken together, these results demonstrated that the PLGA/ PDA-CCMþLight composite had superior wound healing ability compared to that of the other groups.
Histological examination of the wounds revealed that the wound lengths in all treatment groups, except for those in the light and PLGA/PDA groups, were shorter than those in the control group, with the PLGA/PDA-CCMþLight group exhibiting the shortest wound length (Figure S17, Supporting Information).Wound healing ability can be monitored by the degree of collagen deposition. [87]Figure 8D and S18, Supporting Information, show the deposition of newly formed collagen in the wounds.On day 14, the control group demonstrated sparse and disorganized low-level collagen deposition; however, the treated groups, especially the PLGA/PDA-CCMþLight group, exhibited considerably increased deposition of collagens compared with the control group.Wounds subjected to PLGA/PDA-CCMþLight exhibited satisfactory healing, as determined by H&E and Masson staining, with a rapid healing rate and collagen synthesis at the wound site.
[90] Hence, the impact of the nanomaterials on angiogenesis in mice was assessed.Immunofluorescence staining for CD31 (platelet endothelial cell adhesion molecule-1), α-SMA (α-smooth muscle actin), and VEGF was also conducted to quantitatively evaluate neovascularization (Figure S18B-D, Supporting Information).The levels of all three markers in the PLGA/PDA-CCMþLight group were the highest, followed by those in the MOF@CM, MOF@CMþLight, and PLGA/PDAþLight groups.These findings suggest that the   combination of PLGA/PDA-CCM with NIR irradiation may synergistically induce robust angiogenesis, thereby facilitating reepithelialization, collagen formation, and skin maturation, all of which are essential for wound closure.
In previous studies, HKUST-1 was shown to demonstrate strong antibacterial effects and promote cell migration, which could accelerate the wound healing process. [12,91]The MOF@CM groups (including MOF@CMþDark and MOF@CMþLight) exhibited better wound healing efficiency than did the control group, suggesting the potential of HKUST-1 as a wound healing agent.Light, known for its ease of application, noninvasive nature, and spatiotemporal control, has become a promising tool with significant impacts on biomedical applications. [92]The light treatment groups (including PLGA/PDA þ Light and PLGA/PDA-CCM þ Light) exhibited better repair than the dark treatment groups (including PLGA/PDA þDark and PLGA/PDA-CCMþDark), indicating that wound healing could benefit from the photothermal effect.Local hyperthermia induced by photothermal agents under illumination at a specific wavelength may also eliminate bacteria, thereby inhibiting bacteria-derived inflammation and promoting the healing of wounds with bacterial infections. [6,53]Importantly, PTT could promote oxygenation in wounds through increased blood flow, further accelerating healing. [93]Overall, these results suggest that PLGA/ PDA-CCM could be an ideal strategy for promoting infected wound healing due to its intrinsic antioxidant and photothermal effects.

Therapeutic efficacy in treating radiation-related dermatitis
Radiation therapy is a widely used cancer treatment, but it frequently results in radiation dermatitis, [94] with more than 85% of radiotherapy patients experiencing radiation-related skin damage. [95]Therefore, we investigated the potential of MOF@CM and PLGA/PDA-CCM to facilitate recovery from radiation dermatitis.Previous studies have shown that Cu may have antiinflammatory effects. [96]In addition, PDA has antioxidant effects and may contribute to the recovery of radiation wounds. [53,97]fter 14 days of radiotherapy, BALB/c mice with radiation dermatitis were treated with MOF@CM, PLGA/PDA, or PLGA/PDA-CCM and exposed to light (Figure S19, Supporting Information).The healing of dorsal wounds during the treatment was monitored (Figure 9A).
On day 28 postirradiation, a portion of the wound tissue was collected for transcriptome analysis and histological examination.Treatment with MOF@CMþLight, PLGA/PDAþLight, or PLGA/PDA-CCMþLight resulted in reduced skin depression, swelling, and scar area associated with radiation dermatitis compared to those in the control group (Figure 9B).Histological analysis of the PLGA/PDA-CCMþLight group revealed improved epithelial continuity compared to that in the control group (Figure 9C).To further verify the ability of PLGA/PDA-CCM to promote angiogenesis in radiation dermatitis, CD31 and α-SMA expression levels in radiation-related wounds were measured via an immunohistochemical fluorescence assay (Figure 9D).The results indicated the strongest fluorescent signals in the PLGA/PDA-CCMþLight groups compared with those in the control group, suggesting an increase in angiogenic capacity in radiation dermatitis after treatment.Immunofluorescence analysis demonstrated elevated levels of CD31 and α-SMA markers in the skin wounds treated with MOF@CMþLight and PLGA/PDAþLight, with the highest expression observed in the PLGA/PDA-CCMþLight group (Figure 9D).These findings highlight the benefits of PLGA/PDA-CCM in accelerating radiation-induced wound healing.
Further exploration of the mechanism underlying the treatment of radiation dermatitis with PLGA/PDA-CCM involved mRNA sequencing (mRNA-seq) on day 14 post-treatment, during which key genes associated with the remission of radiation dermatitis were assessed, with the untreated group serving as the control.A total of 430 differentially expressed genes (DEGs) were identified in the PLGA/PDA-CCMþLight group relative to the control group, with 208 upregulated and 222 downregulated genes (Figure 9E).Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis revealed that the upregulated DEGs in the PLGA/PDA-CCMþLight group were associated with cellular interactions, extracellular matrix-receptor interactions, and drug metabolism (Figure 9F).Gene Ontology analysis revealed that the DEGs in the PLGA/PDA-CCMþLight group were associated with molecular function, cell component, and biological processes related to cell adhesion, cell proliferation, and skin regeneration (Figure S20, Supporting Information).Compared with those in the control group, the expression of genes encoding harmful inflammatory factors, such as lgf1, ll18r1, and Tgfb3, was reduced in the PLGA/ PDA-CCMþLight group (Figure 9G).Additionally, several genes involved in the positive regulation of angiogenesis, such as Vegfa, Angptl6, Itga2b, and Ngfr, were highly expressed in the PLGA/ PDA-CCMþLight group (Figure 9H), consistent with the results of tissue immunofluorescence.These results indicate that the occurrence of local scarring and rupture of local radiation dermatitis can be improved using PLGA/PDA-CCM in combination with NIR 808 nm laser radiation, and these therapeutic effects are mainly attributed to the anti-inflammatory and proangiogenic effects of HKUST-1 and PLGA/PDA-CCM.
To our knowledge, this is the first study using a sustainedrelease PLGA microsphere platform to deliver nanomaterials encapsulated by CMs for the treatment of radiation dermatitis.Radiation dermatitis is characterized by an excessive inflammatory environment. [83]Our data suggest that the administration of PLGA/PDA-CCM could impact anti-inflammatory metabolic processes to counter the inflammatory response induced by radiation therapy.Under NIR 808 nm radiation, the thermal effect of PLGA/PDA-CCM could alleviate inflammation and promote angiogenesis, which are also beneficial for recovery from radiation dermatitis.

Conclusion
A revolutionary copper nanomaterials-decorated microsphere photothermal platform, known as PLGA/PDA-CCM, has been developed with intrinsic photothermal, anticancer, and antibacterial properties.This pioneering therapeutic platform offers a synergistic approach to combat skin tumors and radiation dermatitis and promote wound healing.PLGA/PDA-CCM is a versatile anticancer strategy that enables targeted delivery, PTT, enhanced antigen presentation, and DC maturation.Notably, the microspheres not only enhanced the photothermal activity but also ensured the sustained release of MOF@CM, thereby promoting prolonged immune activation with the help of CpG.Furthermore, the microsphere platform leverages the combined benefits of local thermal effects and the presence of a Cu-based MOF to support wound healing and alleviate radiation dermatitis by promoting angiogenesis, inflammation, and infection.Due to its biocompatibility and ease of production, PLGA/PDA-CCM holds great promise for clinical translation.Overall, the copper nanomaterials-decorated microspheres represent a novel integrated platform for cancer treatment, radiation dermatitis management, and wound care.This innovative approach offers a promising and comprehensive therapeutic strategy for treating melanoma.

Figure 2 .
Figure 2. Synthesis and characterization of microspheres.A) Schematic illustration showing the synthesis process of PLGA/PDA-CCM, starting with the coating of porous PLGA microspheres (PLGA-MS) with polydopamine (PDA), followed by the adsorption of MOF@CM.B) Optical image of PLGA-MS and PLGA/PDA, showing the appearance of the microspheres.C) Particle size distributions of PLGA-MS and PLGA/PDA, indicating the size distribution of the microspheres.D) SEM images of PLGA-MS and PLGA/PDA, providing a visual representation of the microsphere morphology.Scale bars = 50 μm.E) XPS spectra of microspheres in various binding energy ranges, offering insights into the elemental composition and chemical states of the material.F) FTIR spectroscopy of the PLGA raw materials, porous PLGA microspheres, dopamine, and PLGA/PDA, confirming the successful coating of PDA onto the PLGA microspheres.G) Loading efficiency curves over time for PLGA-MS and PLGA/PDA, demonstrating the ability of the microspheres to adsorb MOF@CM.H) The release profile of MOF@CM from PLGA-MS and PLGA/PDA, showing the sustained release of the loaded MOF@CM over time.I) SEM images of microsphere degradation at different time points, revealing the degradation behavior of the microspheres over time.Scale bars = 50 μm.The data are presented as the mean AE SD (n = 3).**P < 0.01; ***P < 0.001.

Figure 3 .
Figure 3.Effect of PTT on tumor cells and bacteria in vitro.A) Temperature variations in diverse samples subjected to NIR irradiation at a power density of 1.5 W cm À2 were observed at various time intervals, revealing a time-dependent increase in temperature.B) Changes in the temperature of PLGA/PDA-CCM at different concentrations under NIR radiation (1.5 W cm À2 , 5 min), demonstrating the photothermal effect of the microspheres.C) Three heatingcooling cycles of PLGA/PDA-CCM (2 mg mL À1 ) under laser radiation (1.5 W cm À2 ), confirming the stability and reproducibility of the photothermal effect.D) Photothermal images of different samples under NIR radiation, visualizing the photothermal conversion of the microspheres.(1: PBS, 2: MOF@CM, 3: PLGA/PDA, 4: PLGA/PDA-CCM).E) Plate images of E. coli colony formation.F) Representative SEM images of bacteria revealing the morphological changes in the bacteria following PTT.The scale bar = 500 nm.G) The viability of B16F10 cells after different treatments was evaluated by calcein-AM (green) and propidium iodide (PI, red) staining.The scale bar = 100 μm.H) The viability of B16F10 cells was assessed by the CCK-8 assay.I) Confocal microscopy showing the induction of calreticulin (CRT, red) in B16F10 cells at 4 h after different treatments, demonstrating the ICD induced by PTT.The scale bar = 50 μm.J) HMGB1 released by B16F10 cells was detected with an ELISA kit at 24 h after different treatments.K) Extracellular ATP concentration of B16F10 cells at 24 h after different treatments.The data are presented as the mean AE SD (n = 3).***P < 0.001; ****P < 0.0001; n.s.(not significant).

Figure 4 .
Figure 4. Effects of nanomaterials on skin cell migration and immune cells in vitro.A) Images and quantitative relative migration ratios D) of NIH-3t3 cells at different scratch sizes for assessing the effect of the treatments on cell migration.The scale bar = 200 μm.B) Images and quantification E) of Transwell migration of NIH-3t3 cells at 24 h.The scale bar = 100 μm.C) Images and quantification F) of HUVEC tube formation assays.The scale bar = 100 μm.(G) Representative flow cytometry plots of CD11c þ CD86 þ CD80 þ BMDCs after 24 h of treatment with CpG, CM, MOF@CM, PLGA/PDA, or PLGA/PDA-CCM and I) the statistical results.H) Statistical analysis of H-2Kb SIINFEKL-positive cells.J) IL-6 and K) TNF-α levels in the supernatant of BMDCs were detected via an ELISA kit after 24 h of incubation, and cytokine secretion was measured in DCs following treatment.The data are presented as the mean AE SD (n = 3).*P < 0.05; **P < 0.01; ****P < 0.0001; n.s.(not significant).

Figure 9 .
Figure 9. Treatment efficacy for radiation dermatitis.A) Schematic representation of the construction and treatment of the radiation dermatitis model in mice, depicting the experimental setup (n = 6).B) Sequential photographs of different groups of mice illustrating the impact of the treatments on the healing of radiation-induced skin damage.(1: Control, 2: MOF@CMþLight, 3: PLGA/PDAþLight, 4: PLGA/PDA-CCMþLight) C) Histological changes in the skin after treatment are depicted through H&E and Masson staining images of radiation-damaged skin.Scale bars = 400 μm.D) Immunofluorescence staining of CD31 and α-SMA in irradiated skin samples, illustrating the expression and distribution of angiogenesis-related markers in the skin.Scale bars = 100 μm.E) Volcano plots demonstrating the differential expression of genes that were either upregulated or downregulated following treatment with PLGA/PDA-CCMþLight, indicating the gene expression changes induced by the treatment.F) KEGG pathway enrichment analysis of the top 20 upregulated genes in the PLGA/PDA-CCMþLight/Control comparison, providing insights into the biological pathways affected by the treatment.G,H) Relative expression of angiogenesis-and inflammation-associated genes, quantified by the expression levels of genes involved in angiogenesis and inflammation after treatment (n = 3).