Hydrogels are well-stablished materials for biomedical applications such as drug delivery. Their biocompatibility and biodegradability is commonly exploited to encapsulate a payload and deliver it at specific targets. However, the excessive porosity of some of these materials causes the fast leakage of entrapped (bio)molecules. This could lead to i) uncontrolled release profiles; ii) cargo degradation and iii) undesired immunological reactions. Interpenetrating polymer networks (IPN) are frequently used to customize hydrogels properties in an attempt to overcome their intrinsic limitations. The semi-interpenetration of a responsive polyvinylalcohol (PVA)/boronate polymer network (IPN) within alginate hydrogels allowed us to hit two targets with one stone. First, the IPN efficiently sealed larger pores of the hydrogel decreasing leakage of proteins 20-fold compared to plain hydrogels. Second, the degradation of boronate esters by biologically relevant concentrations of hydrogen peroxide (H2O2) made possible the design of a multi-biomarker responsive drug delivery system. Hydrogen peroxide, in bulk or catalytically produced in situ by oxidases in the presence of their biomarker substrates, degraded irreversibly the IPN. As a result, the pores of the hydrogel are reopened releasing the entrapped proteins. The developed strategy is independent of the hydrogel source and can be extended to other porous materials. In addition, the lack of cytotoxicity of aryboronates as well as the biocompatibility of both PVA and alginate, makes this material suitable for “smart” delivery of encapsulated protein drugs.

Interpenetrating responsive polymer networks within hydrogels for "smart" drug delivery

ACS Fall 2021

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.