New technologies rely on the development of new materials, and these may simply be the innovative combination of known components. The structural combination of a polymer hydrogel network with a nanoparticle (metals, non‐metals, metal oxides, and polymeric moieties) holds the promise of providing superior functionality to the composite material with applications in diverse fields, including catalysis, electronics, bio‐sensing, drug delivery, nano‐medicine, and environmental remediation. This mixing may result in a synergistic property enhancement of each component: for example, the mechanical strength of the hydrogel and concomitantly decrease aggregation of the nanoparticles. These mutual benefits and the associated potential applications have seen a surge of interest in the past decade from multi‐disciplinary research groups. Recent advances in nanoparticle–hydrogel composites are herein reviewed with a focus on their synthesis, design, potential applications, and the inherent challenges accompanying these exciting materials.

In situ gel delivery systems are preferred over conventional systems due to sustained and prolonged release action of therapeutic payload onto the targeted site. Thermogel, a form of in situ gel-forming polymeric formulation, undergoes sol–gel transition after administration into the body. At room temperature, the system is an aqueous polymer solution that easily entraps therapeutic payload by mixing. Upon injection, the higher physiological temperature causes gelation in situ because of the presence of thermosensitive polymers. The gel degrades gradually over time, allowing sustained release of therapeutics localized to the site of interest. This minimizes systemic toxicity and improved efficacy of drug release to the targeted site. Thermogel properties can be easily altered for specific applications via substitution and modification of components in diblock and triblock copolymer systems. The feasibility of fine-tuning allows modifications to biodegradability, biocompatibility, biological functionalization, mechanical properties, and drug release profile. This review summarized recent development in thermogel research with a focus on synthesis and self-assembly mechanisms, gel biodegradability, and applications for drug delivery, cell encapsulation and tissue engineering. This review also assessed inadequacy of material properties as a stand-alone factor on therapeutic action efficacy in human trials, with a focus on OncoGel, an experimental thermogel that demonstrated excellent individual or synergistic drug delivery system in preclinical trials but lacked therapeutic impact in human trials. Detailed analysis from all aspects must be considered during technology development for a successful thermogel platform in drug delivery and tissue engineering.

The recently developed poly(glycerol sebacate) (PGS) has been gaining attraction as a biomaterial for tissue engineering applications. Reported in 2002, a simple polycondensation method was developed to synthesize PGS for soft tissue engineering applications. It has since become a highly sought after biomaterial due to its soft, robust and flexible characteristics and it is relatively low cost compared to other biodegradable elastomers currently available in the market. We summarise in this review, the various synthetic approaches of PGS and highlight selected applications in nerve guidance, soft tissue regeneration, vascular and myocardial tissue regeneration, blood vessel reconstruction, drug delivery, and the replacement of photoreceptor cells. A critical assessment of the material is provided as a scope for future improvement. The future outlook of this material is also provided at the end of this review.