Nanotechnology-based development of drug delivery systems is an attractive area of research in formulation driven R&D laboratories that makes administration of new and complex drugs feasible. It plays a significant role in the design of novel dosage forms by attributing target specific drug delivery, controlled drug release, improved, patient friendly drug regimen and lower side effects. Polysaccharides, especially chitosan, occupy an important place and are widely used in nano drug delivery systems owing to their biocompatibility and biodegradability. This review focuses on chitosan nanoparticles and envisages to provide an insight into the chemistry, properties, drug release mechanisms, preparation techniques and the vast evolving landscape of diverse applications across disease categories leading to development of better therapeutics and superior clinical outcomes. It summarizes recent advancement in the development and utility of functionalized chitosan in anticancer therapeutics, cancer immunotherapy, theranostics and multistage delivery systems.

Oral squamous cell carcinoma (OSCC) is the most common type of oral cancer; it involves damage to oral epithelial cells due to accumulation of multiple genetic mutations in the cells. OSCC remains major cause of morbidity and mortality in patients with head and neck cancers. Tobacco, smoking, alcohol consumption alone or with chewing tobacco, and betel quid are potential carcinogens contributing to the high occurrence of OSCC. Current treatment modalities for OSCC like chemoradiotherapy, surgery, EGFR inhibitors and COX-2 inhibitors, and photodynamic therapy have led to the major problems related to non-specific cell death. Nanoengineered systems offer solutions to these problems that not only minimize the major drawbacks of nonspecific cell death but also maximize the efficacy of the cancer therapeutic agents. Various efficacious nanotechnology-based carrier systems are being widely investigated for their potential in OSCC treatment: polymeric nanoparticles, polymeric micelles, nanoemulsions and layered nanoemulsions, nanoliposomes, solid lipid nanoparticles and nanolipid carriers, cyclodextrin complexes, hydrogels, metallic nanoparticles, nanocarbon tubes, and receptor mediated drug delivery systems. We highlight the etiology, line of the treatment and chemopreventive measures related to OSCC. We focus on data available in the research carried out worldwide in past 15 years related to the management of OSCC.

Introduction: The targeted delivery of anti-cancer agents to the tumour is a major challenge because most of the drugs show off-target effect resulting in nonspecific cell death. Multi-functionalized metallic nanoparticles (NPs) are explored as a new carrier system in the era of cancer therapeutics. Researchers have investigated the potential of metallic NPs to target tumour cells by active and passive mechanisms, thereby reducing the off-target effects of the anticancer agents. Moreover, photocatalytic activity of upconversion nanoparticles (UCNPs) and the enhanced permeation and retention (EPR) effect have also gained a wide potential in the treatment of cancer. Recent advancement in the field of nanotechnology highlights their potency for cancer therapy. Areas covered: This review summarizes the types of gold and silver metallic NPs with the targeting mechanisms and their potentiality in cancer therapy. Expert opinion: Recent advances in the field of nanotechnology for cancer therapy offers high specificity and targeting efficiency. Targeting the tumour cells through mechanistic pathways using metallic NPs for the disruption/alteration of the molecular profile and survival rate of the tumour cells has led to an effective approach for cancer therapeutics. This alteration in the survival rate of the tumour cells might decrease the proliferation thereby resulting in more efficient management in the treatment of cancer.

Microbial pathogens are the most prevalent cause of chronic infections and fatalities around the world. Antimicrobial agents including antibiotics have been frequently utilized in the treatment of infections due to their exceptional outcomes. However, their widespread use has resulted in the emergence of multidrug-resistant strains of bacteria, fungi, viruses, and parasites. Furthermore, due to inherent resistance to antimicrobial drugs and the host defence system, the advent of new infectious diseases, chronic infections, and the occurrence of biofilms pose a tougher challenge to the current treatment line. Essential oils (EOs) and their biologically and structurally diverse constituents provide a distinctive, inexhaustible, and novel source of antibacterial, antiviral, antifungal, and antiparasitic agents. However, due to their volatile nature, chemical susceptibility, and poor solubility, their development as antimicrobials is limited. Nanoparticles composed of biodegradable polymeric and inorganic materials have been studied extensively to overcome these limitations. Nanoparticles are being investigated as nanocarriers for antimicrobial delivery, antimicrobial coatings for food products, implantable devices, and medicinal materials in dressings and packaging materials due to their intrinsic capacity to overcome microbial resistance. Essential oil-loaded nanoparticles may offer the potential benefits of synergism in antimicrobial activity, high loading capacity, increased solubility, decreased volatility, chemical stability, and enhancement of the bioavailability and shelf life of EOs and their constituents. This review focuses on the potentiation of the antimicrobial activity of essential oils and their constituents in nanoparticulate delivery systems for a wide range of applications, such as food preservation, packaging, and alternative treatments for infectious diseases.

One of the major impediments to drug development is low aqueous solubility and thus poor bioavailability, which leads to insufficient clinical utility. Around 70–80% of drugs in the discovery pipeline are suffering from poor aqueous solubility and poor bioavailability, which is a major challenge when one has to develop an ocular drug delivery system. The outer lipid layer, pre-corneal, dynamic, and static ocular barriers limit drug availability to the targeted ocular tissues. Biopharmaceutical Classification System (BCS) class II drugs with adequate permeability and limited or no aqueous solubility have been extensively studied for various polymer-based solubility enhancement approaches. The hydrophilic nature of cellulosic polymers and their tunable properties make them the polymers of choice in various solubility-enhancement techniques. This review focuses on various cellulose derivatives, specifically, their role, current status and novel modified cellulosic polymers for enhancing the bioavailability of BCS class II drugs in ocular drug delivery systems.

Rheumatoid arthritis (RA) is a systemic autoimmune disease manifested by chronic joint inflammation leading to severe disability and premature mortality. With a global prevalence of about 0.3%-1% RA is 3-5 times more prevalent in women than in men. There is no known cure for RA; the ultimate goal for treatment of RA is to provide symptomatic relief. The treatment regimen for RA involves frequent drug administration and high doses of NSAIDs such as indomethacin, diclofenac, ibuprofen, celecoxib, etorcoxib. These potent drugs often have off target effects which drastically decreases patient compliance. Moreover, conventional non-steroidal anti-inflammatory have many formulation challenges like low solubility and permeability, poor bioavailability, degradation by gastrointestinal enzymes, food interactions and toxicity. To overcome these barriers, researchers have turned to topical route of drug administration, which has superior patience compliance and they also bypass the first past effect experienced with conventional oral administration. Furthermore, to enhance the permeation of drug through the layers of the skin and reach the site of inflammation, nanosized carriers have been designed such as liposomes, nanoemulsions, niosomes, ethosomes, solid lipid nanoparticles and transferosomes. These drug delivery systems are non-toxic and have high drug encapsulation efficiency and they also provide sustained release of drug. This review discusses the effect of formulation composition on the physiochemical properties of these nanocarriers in terms of particle size, surface charge, drug entrapment and also drug release profile thus providing a landscape of topically used nanoformulations for symptomatic treatment of RA.