Ferulic acid (FA) is an antioxidant and photoprotective agent used in biomedical and cosmetic formulations to prevent skin cancer and senescence. Although FA exhibits numerous health benefits, physicochemical instability leading to decomposition hinders its efficacy. To minimize inherent decomposition, a FA-containing biodegradable polymer was prepared via solution polymerization to chemically incorporate FA into a poly(anhydride-ester). The polymer was characterized using nuclear magnetic resonance and infrared spectroscopies. The molecular weight and thermal properties were also determined. In vitro studies demonstrated that the polymer was hydrolytically degradable, thus providing controlled release of the chemically incorporated bioactive with no detectable decomposition. The polymer degradation products were found to exhibit antioxidant and antibacterial activity comparable to free FA and in vitro cell viability studies demonstrated that the polymer is non-cytotoxic towards fibroblasts. This renders the polymer a potential candidate for use as a controlled release system for skin care formulations.

Many currently used antibiotics suffer from issues such as systemic toxicity, short half-life, and increased susceptibility to bacterial resistance. Although most antibiotic classes are administered systemically through oral or intravenous routes, a more efficient delivery system is needed. This review discusses the chemical conjugation of antibiotics to polymers, achieved by forming covalent bonds between antibiotics and a pre-existing polymer or by developing novel antibiotic-containing polymers. Through conjugating antibiotics to polymers, unique polymer properties can be taken advantage of. These polymeric antibiotics display controlled, sustained drug release and vary in antibiotic class type, synthetic method, polymer composition, bond lability, and antibacterial activity. The polymer synthesis, characterization, drug release, and antibacterial activities, if applicable, will be presented to offer a detailed overview of each system.

Significant and promising advances have been made in the polymer field for controlled and sustained bioactive delivery. Traditionally, small molecule bioactives have been physically incorporated into biodegradable polymers; however, chemical incorporation allows for higher drug loading, more controlled release, and enhanced processability. Moreover, the advent of bioactive-containing monomer polymerization and hydrolytic biodegradability allows for tunable bioactive loading without yielding a polymer residue. In this review, we highlight the chemical incorporation of different bioactive classes into novel biodegradable and biocompatible polymers. The polymer design, synthesis, and formulation are summarized in addition to the evaluation of bioactivity retention upon release via in vitro and in vivo studies.