Anis Abdul Karim

Nanoparticle–Hydrogel Composites: Concept, Design, and Applications of These Promising, Multi‐Functional Materials

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.

Emerging Supramolecular Therapeutic Carriers Based on Host–Guest Interactions

Recent advances in host-guest chemistry have significantly influenced the construction of supramolecular soft biomaterials. The highly selective and non-covalent interactions provide vast possibilities of manipulating supramolecular self-assemblies at the molecular level, allowing a rational design to control the sizes and morphologies of the resultant objects as carrier vehicles in a delivery system. In this Focus Review, the most recent developments of supramolecular self-assemblies through host-guest inclusion, including nanoparticles, micelles, vesicles, hydrogels, and various stimuli-responsive morphology transition materials are presented. These sophisticated materials with diverse functions, oriented towards therapeutic agent delivery, are further summarized into several active domains in the areas of drug delivery, gene delivery, co-delivery and site-specific targeting deliveries. Finally, the possible strategies for future design of multifunctional delivery carriers by combining host-guest chemistry with biological interface science are proposed.

Current treatment options and drug delivery systems as potential therapeutic agents for ovarian cancer: a review.

Ovarian cancer is one of the most common and deadliest gynecologic cancer with about 75% of the patients presenting in advanced stages. The introduction of intraperitoneal chemotherapy in 2006 had led to a 16 month improvement in the overall survival. However, catheter-related complication and the complexity of the procedure had deterred intraperitoneal route as the preferred route of treatment. Other alternative treatments had been developed by incorporating other FDA-approved agents or procedures such as pegylated liposomal doxorubicin (PLD), hyperthermic intraoperative intraperitoneal chemotherapy (HIPEC) and the administration of bevacizumab. Various clinical trials were conducted on these alternatives as both the first-line treatment and second- or third-line therapy for the recurrent disease. The outcome of these studies were summarized and discussed. A prospective improvement in the treatment of ovarian cancer could be done through the use of a drug delivery system. Selected promising recent developments in ovarian cancer drug delivery systems using different delivery vehicles, surface modifications, materials and drugs were also reviewed.

Poly(glycerol sebacate) biomaterial: synthesis and biomedical applications

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.

Modification of Thermal and Mechanical Properties of PEG-PPG-PEG Copolymer (F127) with MA-POSS

Pluronic F127 exhibits thermogelling behaviour at 20–30 °C via a micelle packing mechanism. Disruption of the micelle packing increases the sol-gel temperature, but results in the decrease of modulus. Herein, we reported a method to modify F127 with polyhedral oligosilsesquioxane (POSS) to impart a higher gelling temperature without yielding the property and strength of the thermogel. The thermal degradation temperature was enhanced to 15 °C after POSS incorporation and the gelling temperature shifted 10 °C higher, without sacrificing the modulus of the gel. Rheological studies supported the claim that the gel property was reinforced after POSS incorporation. F127-POSS copolymer matrix stored more energy from POSS reinforcement, which saw larger Lissajous curve areas before the collapse of the microstructure for the same amount of stress applied. These results indicated that modification with POSS would raise the sol-gel transition temperature without sacrificing the modulus of the gel.

A Recent Perspective on Noncovalently Formed Polymeric Hydrogels

Chemically crosslinked covalent hydrogels form a permanent and often strong network, and have been extensively used so far in drug delivery and tissue engineering. However, it is more difficult to induce dynamic and highly tunable changes in these hydrogels. Noncovalently formed hydrogels show promise as inherently reversible systems with an ability to change in response to dynamic environments, and have garnered strong interest recently. In this Personal Account, we elucidate a few key attractive properties of noncovalent hydrogels and describe recent developments in hydrogels crosslinked using various different noncovalent interactions. These hydrogels offer huge control for modulating material properties and could be more relevant mimics for biological systems.