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.

Liposomes are nanocarriers that have been widely used for site-specific delivery of chemotherapeutic drugs due to their ease of surface modification with targeting ligands. The pH-responsive properties of hyaluronic acid (HA)-functionalized β-cyclodextrin gemcitabine nanoliposomes (HA-β-CD-GEM-NLs) prepared by the thin-film hydration method were investigated in this study. The influence of internal microenvironmental pH (5.5, 6.8, and 7.4) of liposomes containing a β-CD-GEM inclusion complex on drug loading, encapsulation efficiency, and release was also investigated. The optimized formulation was functionalized with HA and assessed for particle size, polydispersity index (PDI), zeta potential, morphology, and compatibility using FTIR. The optimized formulation had a particle size of 275.7 nm, a zeta potential of -7.5 mV, and a PDI of 0.139 with 78.37% encapsulation efficiency and 13.06 % drug loading. FTIR studies were carried out for compatibility analysis of formulation components, and morphological analysis showed vesicular liposomes and cube-like structures before and after HA modification, respectively. In vitro release studies demonstrated significantly higher GEM release at acidic pH (5.3) compared to pH 6.8 and 7.4, ensuing Fickian diffusion [K1] kinetics. Stability studies indicated good stability at 25 ± 2 °C/60 ± 5% RH. These results display that HA-β-CD-GEM-NLs are promising pH-responsive nanocarriers with drug release in the acidic environment, therefore not only maximizing the drug release at the targeted site i.e. tumor microenvironment but also avoiding the drug related toxicities. [K1]added

Osteoarthritis (OA) is the most prevalent degenerative joint disease worldwide. OA involves chronic pain, subchondral bone remodeling, synovial inflammation, and progressive cartilage degeneration. Gut microbiota (GM) dysbiosis disturbs metabolic processes and systemic inflammation and induces joint deterioration through the gut-joint axis. Conventional pharmacological interventions are associated with adverse effects upon long-term use and merely alleviate symptoms but do not prevent the disease progression. Nutraceuticals are alternative for the treatment of OA due to their safety, multimodal activity, and potential disease-modifying properties. Among them, amino sugar derivatives such as glucosamine sulfate (GS) and chondroitin sulfate (CS) naturally occur in cartilage extracellular matrix and exhibit a range of biological actions. GS and CS exert their action by decreasing catabolic enzymes (MMPs, ADAMTS), suppressing pro-inflammatory signaling pathways (NF-κB, MAPK), stimulating anabolic processes (type II collagen and aggrecan synthesis), controlling oxidative stress, and blocking chondrocyte apoptosis. This review, in addition to future works, presents in-vitro, in-vivo, and clinical investigations to critically evaluate the molecular activities of CS and GS in the regulation of cartilage-related and inflammatory pathways in knee OA. We also emphasize their interactions with the GM, their synergistic potential, and the application of nanotechnology strategies to enhance therapeutic efficacy and bioavailability in OA. Graphical abstract

The aim of this study was to prepare ibuprofen-loaded glycerin nanoparticle (IBU-GNP) based hydrogel for improved antiinflammatory effect. Ibuprofen (IBU) has low oral bioavailability and topical permeability because of poor solubility and transdermal permeability barriers. Glycerin nanoparticles (GNPs) are emerging nanotechnology for solubility improvement with the help of glycerin. Precipitation technique was opted to prepare IBU-GNPs, and the prepared nanoparticles (NPs) were subjected to appropriate in-vitro characterization techniques. IBU-GNPs revealed a uniform average diameter of 492.9 ± 44.2 nm. IBU-GNPs were formulated in hydrogel dosage form for topical application using carbopol 934 (2% w/v). Physical characterization, in-vitro release, and in-vivo antiinflammatory study in comparison to marketed IBU gel was performed for IBU-GNP hydrogel. The in-vitro drug release data revealed quick and sustained release behavior, which best fit the Higuchi model and followed Fickian diffusion as the release mechanism. IBU-GNP hydrogel rapidly lowered inflammation induced by carrageenan, followed by a sustained antiinflammatory activity, confirming an in vitro release pattern.