Magnetic gold nanoparticles (mGNP) have become a great interest of research for nanomaterial scientists because of their significant magnetic and plasmonic properties applicable in biomedical applications. Various synthetic approaches and surface modification techniques have been used for mGNP including the most common being the coprecipitation, thermal decomposition, and microemulsion methods in addition to the Brust Schiffrin technique, which involves the reduction of metal precursors in a two-phase system (water and toluene) in the presence of alkanethiol. The hybrid magnetic–plasmonic nanoparticles based on iron core and gold shell are being considered as potential theranostic agents. In this critical review, in addition to future works, we have summarized recent developments for synthesis and surface modification of mGNP with their applications in modern biomedical science such as drug and gene delivery, bioimaging, biosensing, and neuro-regeneration, neuro-degenerative and arthritic disorders. This review includes techniques and biological applications of mGNP majorly based on research from the previous six years.

Poor control towards glycemic levels among diabetic patients may lead to severe micro/macro-vascular and neuropathic complexities. Proper functioning of alpha-beta cells of pancreases is required to attain long term glycemic control among type 2 diabetics. The recent developments to manage diabetes are focused on controlling the insulin-glucagon secretions from the pancreases. DPP-4 inhibitors class of drugs after elevating GLP-1/GIP (incretins) levels in the blood, not only raise the insulin levels but also suppress the glucagon level. Vildagliptin (VI) is a potent DPP-4 inhibitor with least adverse events compared to other DPP-4 inhibitors. We encapsulated VI into 3D nanocube that gets bind to the DNA due to secondary amine in its chemical structure. DNA-nanocube being negatively charged was incubated with the PLL to attain positive surface. Ultimately VI loaded nanocubes were coated with the negatively charged Na-alginate via electrostatic attraction method to get stable spherical nanospheres for oral delivery of VI. Nanospheres were evaluated physically through native PAGE analysis, DSC, TGA, dissolution testing, XRD and FTIR. We attained uniformed and spherical nanospheres with stable topology, nanoscale size precision (40-150 nm in diameter), Entrapment efficiency (up to 90%), prolonged drug release (13 ± 4 h) at basic pH, and superior oral antidiabetic effects with improved GLP1 and glycemic levels. The formulated nanospheres attained size uniformity and better therapeutic outcomes in terms of reduced adverse events and better control of glycemic levels than previously reported methods with decreased dosage frequency tested in Db/Db mice.

Rheumatoid Arthritis (RA) is an autoimmune disorder that hinders the normal functioning of bones and joints and reduces the quality of human life. Every year, millions of people are diagnosed with RA worldwide, particularly among elderly individuals and women. Therefore, there is a global need to develop new biomaterials, medicines and therapeutic methods for treating RA. This will improve the Healthcare Access and Quality Index and also relieve administrative and financial burdens on healthcare service providers at a global scale. Hydrogels are soft and cross-linked polymeric materials that can store a chunk of fluids, drugs and biomolecules for hydration and therapeutic applications. Hydrogels are biocompatible and exhibit excellent mechanical properties, such as providing elastic cushions to articulating joints by mimicking the natural synovial fluid. Hence, hydrogels create a natural biological environment within the synovial cavity to reduce autoimmune reactions and friction. Hydrogels also lubricate the articulating joint surfaces to prevent degradation of synovial surfaces of bones and cartilage, thus exhibiting high potential for treating RA. This work reviews the progress in injectable and implantable hydrogels, synthesis methods, types of drugs, advantages and challenges. Additionally, it discusses the role of hydrogels in targeted drug delivery, mechanistic behaviour and tribological performance for RA treatment.