Healthcare is a challenging problem faced by every country in the world. In the United States, it is a particularly important and urgent issue due to the 78 million baby boomers born between 1946 and 1964. Early this year, the first of these boomers turned 65, the typical age set for retirement. According to government projections, 26 percent of the U.S. population will be aged 65 or older in 2030, compared with 17 percent today. The aged population is expected to change the entire healthcare system by demanding a greater focus more on well-ness and prevention efforts. At the same time, it will spur technological innovation in order to make medical intervention more effective and more affordable
What can the materials research community offer in addressing the healthcare problem? The answer can be easily formulated into an extremely long list of fascinating opportunities.1 After all, advanced materials are invaluable and indispensable for the following applications: i) as substrates for ultrasensitive detection of disease markers; ii) as contrast agents for essentially all types of imaging modalities; iii) as carriers for drug delivery and controlled release; and iv) as scaffolds for tissue engineering or regenerative medicine. In addition to materials that address one specific application listed above, there is a strong effort in developing materials (or systems) integrated with at least two different capabilities. A good example is the so-called “theranostic agents” that have the dual functionality for both diagnosis and therapy. These applications have the potential to cause a paradigm shift for healthcare by dramatically changing how a disease is diagnosed, treated, and prevented in the future. Significantly, all these applications require the design and synthesis of new materials with well-defined and controllable compositions, surface chemistries, and other physicochemical properties.
There are already many successful stories of the utilization of functional materials to advance healthcare. For example, lipid vesicles (commonly known as liposomes) and polymer particles have long been used as carriers to improve the pharmaceutical efficacy or dosing of clinically approved drugs. In some cases, the delivery systems also provide life-cycle extension of drugs after expiration of patents, allowing pharmaceutical companies to maintain stable revenues for longer times and thus reduce the costs of branded drugs. Inorganic nanoparticles such as those with superparamagnetic properties have been commercialized for the purification, separation, and detection of biological species (e.g., biomarkers) since the early 80's. This class of materials has also been extensively exploited as vectors for drug delivery and as molecular contrast agents for magnetic resonance imaging (MRI). Exemplified by the Guerbet Group's Endorem, iron oxide-based nanoparticles have been marketed as MRI contrast agents for clinical use by a number of companies. Gold nanopar-ticles have received renewed interest for their spectacular properties, which result in localized surface plasmon resonance and are responsible for their ability to strongly scatter and absorb light at tunable wavelengths. These effects have been used to develop sensors for colorimetric detection of nucleic acids and proteins with remarkably high sensitivity. The plasmon resonance also creates a strong electromagnetic field on the particle surface, which can enhance the cross section of Raman up to one billion fold, potentially enabling the development of non-invasive methods for detecting the biomarker indicative of a specific disease or infection at the single-molecule level.
As the first Chairman of the Editorial Advisory Board, I am honored to present the inaugural issue of Advanced Healthcare Materials with an array of diverse and exciting contributions. Michael Messenger and Paul Tomlins from the UK review the current regulatory framework and standards portfolio and then discuss their role in the com-mercialization of potential regenerative medicine products. Leone Spiccia, Bim Graham, Holger Stefan, and co-workers from Australia review recent developments in the use of nanomaterials for targeting, imaging, and treating cancer. Jason Burdick and Glen Prestwich from the USA review the biomedical applications of hydrogels based on hyaluronic acid, an immunoneutral polysaccharide that is ubiquitous in the human body. Taolei Sun and Guangyan Qing from Germany highlight recent developments of smart polymers for modulating the interfacial behavior of biological entities such as cells and biomolecules. Robert Langer, Omid Farokhzad, Rohit Karnik, and co-workers from the USA report a simple and versatile platform for producing nanoparticles by using a simple configuration of 3D hydrodynamic flow focusing. Yanyan Jiang and co-workers from China report the synthesis of RGD-modified, PEGylated polyamidoamine dendrimers conjugated with doxoru-bicin (DOX) for both in vitro and in vivo cancer treatment. Shoji Takeuchi and co-workers from Japan report a new method for fabricating uniform, cell-dense, millimeter-thick tissues using monodisperse collagen gel beads covered with cells, which is potentially useful in the fabrication of complex, functional tissues. Daniel Anderson, Robert Langer, and co-workers from the USA report the development of a new family of biodegradable poly(ester amide) elas-tomers whose compliance under force resembles more closely the elastomeric nature of many human tissues. David Mooney and co-workers from the USA report an optical technique based on metal-enhanced fluorescence for quanti-fying bacterial attachment, which is the first step of biofilm formation. Samir Mitragotri, Michael Rubner, and co-workers from the USA report the fabrication of cell-based drug-delivery devices by adding backpacks (which could be loaded with contrast agents and therapeutic drugs) to the surfaces of macrophages. Catherine Picart and co-workers from France report a biomimetic film that has both tunable mechanical properties and matrix-bound presentation of the growth factor bone morphogenetic protein 2 (BMP-2) for regulating signaling sensitivity and cytoskeleton dynamics. Sander Leeuwenburg and co-workers from The Netherlands report the fabrication of bio-degradable gels from oppositely charged gelatin nanospheres, which show great potential as injectable gels for tissue regeneration. Finally, I would like to take this opportunity to thank the editorial and production team at Advanced Healthcare Materials for their outstanding assistance and support. I am also extremely grateful to the Editorial Advisory Board members for their prompt responses to our invitations, as well as their enthusiasm for and commitment to this exciting project. Together, we hope that Advanced Healthcare Materials will provide a valuable forum for high-quality publications and scientific disclosure that aim to meet the healthcare challenge.