Translational Biomedicine

Introduction

The ability to isolate cells from individual patientsofferstremendous promise if those cells can be used to generatefunctionaltissue replacements or used in disease modeling todetermine optimal treatment strategies. Here, we review recentprogress in the use of hydrogels to create artificial cellularmicroenvironments for personalized tissue engineering andregenerative medicine applications, as well as to developpersonalized disease models. Continued progress in thedevelopment of engineered hydrogels, in combination withother emerging technologies, will be essential to realize theimmense potential of personalized medicine.

Analysis

The field of regenerative medicine has tremendous potentialfor improved treatment outcomes and has been stimulated byadvances made in bioengineering over the last few decades. Thestrategies of engineering tissues and assembling functionalconstructs that are capable of restoring, retaining, andrevitalizing lost tissues and organs have impacted the wholespectrum of medicine and health care. The high water contentof hydrogels can provide an ideal environment for cell survival,and structure which mimics the nativetissues. Hydrogel systemshave been serving as a supportive matrix for cell immobilizationand growth factor delivery. This review outlines a briefdescription of the properties, structure, synthesis andfabrication methods, applications, and future perspectives ofsmart hydrogels in tissue engineering. Understanding cellbehavior within the extracellular matrix is essential for theimplementation of biomaterials in medical applications.Conjugation of bioactive molecules to hydrogel scaffolds impartsthe materials with biological cues necessary for controlling cellbehavior such as adhesion, growth and migration. Photo-induced ligation is a powerful tool to precisely control when andwhere such bioactivity can be initiated. In this approach,reactive groups such as thiol, amine and aldehyde are maskedwith photolabile moieties, which can be photo-released toparticipate in click reactions, such as Michael addition andoxime ligation. New chromophores with long wavelength visiblelight absorption are also examined for potential employment inlight-induced bioconjugation.

Conclusion

In tissue engineering, i.e., in combined advanced technologiesto replace damaged or missing parts of living tissues, emergingstrategies strongly point toward the use of hydrogels also fortheir ability of being vehicles for local controlled drug delivery.The investigation of drug release mechanisms in such matricesthus plays a key role in the design of smart system but literatureis still very controversial on theoreticalinterpretations andunderstanding of available data. The proportion of this effectwas directly linked to hydrogel mesh size, thus carrying intrinsicnovelty, but also complexity, and suggesting that not only strictlyhydrodynamic effects should be considered but alsoelectrostaticinteractions between polymer chains and drugmolecules might be key players in avoiding fluoresceinaggregation and also affectingdiffusivity.