Macromolecular Bioscience

Front Cover: A hybrid material with excellent mechanical and biological properties was produced by electrospinning a cosolution of PET and collagen. Fibers of different compositions and morphologies were intermingled, resulting in better cell attachment and proliferation. These materials are potential candidates to be used as vascular grafts. Further details can be found in the article by M. C. Burrows, V. M. Zamarion, F. B. Filippin-Monteiro, D. C. Schuck, H. E. Toma, A. Campa, C. R. S. Garcia, and L. H. Catalani* on page 1660.

Back Cover: Novel degradable and antibacterial polymers are made by clicking hydantoin moieties to polycaprolactone. The degradability of polycaprolactone was retained and a fast antibacterial action towards Gram-negative and -positive cells was introduced thereby. Further details can be found in the article by L. Tan, S. Maji, C. Mattheis, Y. Chen, and S. Agarwal* on page 1721.

CPs are considered as novel candidates to serve as multifunctional delivery systems due to their high fluorescence quantum yield, good photostability, and low cytotoxicity. This feature article mainly focuses on CP-based multifunctional non-viral delivery systems for drug, protein, gene, and cell delivery.

The use of SPIO nanoparticles encapsulated into PLG microspheres as a tracking vehicle for injectable microsphere delivery in static and dynamic tissues is discussed. The retention of tracer microspheres in vivo, 28 d post injection, is demonstrated. This suggests the potential benefit of including SPIO encapsulated microspheres in future drug delivery applications to track therapy.

Nanoscale ocular drug carriers are developed from phenylboronic acid modified poly(D,L-lactide)-b-dextran nanoparticles. These particles of approximately 28 nm in diameter are able to encapsulate clinically relevant dosage of drugs and release them at a sustained rate. The drug carriers, by targeting the ocular mucosa, may reduce the clearance of drugs from tear turnover, and thus improve the ocular bioavailability of topically administered drugs.

Natural biomaterials and human cells are used to develop a tri-layer human skin equivalent. The hypodermis is formed in a silk sponge and the epidermal/dermal layer with a collagen gel. They are cultured together forming a physiologically relevant skin equivalent ultimately as a replacement for animal testing, studying skin biology or as a skin graft.

Sulfonate- and phosphonate-functionalized polystyrene nanoparticles exhibit a pronounced uptake by immature and mature dendritic cells compared to unfunctionalized nanoparticles. Moreover, sulfonated and phosphonated polystyrene nanoparticles trigger iDC maturation accompanied with a strengthened CD4⁺ T cell stimulatory capacity and elevated IFN-γ levels, indicating a Th1 response.

Polyethylene terephthalate surfaces micropatterned with both RGDS and WQPPRARI peptides are studied in order to control endothelial cell adhesion under shear stress. These materials allow creating geometries on surface to guide cell orientation under shear stress and controlling surface chemical composition to modulate cell behavior.

Electrospinning of a PET/collagen co-solution produces a mat of heterogeneous nature in which fibers of mostly pure collagen are intermingled with fibers of pure PET. The PET/collagen ratio defines several characteristics of these mats, including morphology and composition of the fibers. In vitro cell culture indicates a potential use of this material as vascular grafts.

Silk films with grooved surface topographies are evaluated for their effect on the organization and osteogenic differentiation of hMSCs. The patterned silk films support osteogenic differentiation while also inducing robust alignment of the cells and extracellular matrix. Multilayered structures form spontaneously and resemble the cellular architecture of native cortical bone lamellae.

Polyethylenimines are simply modified by N-isopropylacrylamide via Michael addition. The optimized transfection efficiency of the obtained derivatives is 18-fold higher than that of pristine PEI-25K. Furthermore, the modified PEI has not only great endocytosis ability but also amazing nuclear uptake ability.

An amphoteric aliphatic polycarbonate functionalized with amine and carboxyl groups is designed and prepared by one-step enzymatic biosynthesis. The simultaneous incorporation of amine and carboxyl functionalities provides the copolymer with a pH-tunable self-aggregation feature, leading to multiple aggregation states including precipitated agglomerate, well-dispersed positively or negatively charged nanoparticles in a controlled manner.

Linear polyurethanes prepared from naturally occurring fatty acid-derived diols are surface modified via aminolysis treatment as a previous step to ionically immobilize bioactive chondroitin sulfate (CS). CS immobilization significantly increases surface wettability, as well as enhances osteoblast cytocompatibility in comparison with base polyurethanes.

Microbial growth can lead to failure of dimethacrylate-based polymers. This study demonstrates for the first time that dimethacrylate polymer degree of conversion (DC), which can vary significantly for materials polymerized in situ, alters bacterial biofilms. The predominant property responsible for this effect is leachable release and not tethered surface methacrylates.

Treatment of cancer still suffers from moderate efficiency and serious side-effects. Most currently used chemotherapeutics exhibit non-specific toxicity, moreover, only a small fraction of the administered dose reaches the tumor. This study proposes a universal drug carrier targeted to cancer cells, enabling preferential action of the drug inside the tumor and suppression of its toxicity.

Poly(ε-caprolactone) is equipped with antibacterial properties via introduction of pendant hydantoin moieties by means of click-chemistry which furthermore enhances the mechanical and thermal stability compared to linear PCL. The degradability of the material is retained and a fast antibacterial action toward Gram-negative and positive cells is introduced thereby.

It is demonstrated that chemically modified glycogen as a biodegradable and inexpensive material coming from renewable resources (and which is present normally in the human body in amounts of ≈100 g depending on nutritional status) could be useful as a polymer nanocarrier for in vivo imaging.