Nanocarriers are defined as structures and devices that are constructed using nanomaterials which add functionality to the encapsulants. Being small in size and having a customized surface, improved solubility and multi-functionality, it is envisaged that nanoparticles will continue to create new biomedical applications owing to their stability, solubility, and bioavailability, as well as controlled release of drugs. The type and physiochemical as well as morphological attributes of nanoparticles influence their interaction with living cells and determine the route of administration, clearance, as well as related toxic effects. Over the past decades, biodegradable polymers such as polysaccharides have drowned a great deal of attention in pharmaceutical industry with respect to designing of drug delivery systems. On this note, biodegradable polymeric nanocarrier is deemed to control the release of the drug, stabilize labile molecules from degradation and site-specific drug targeting, with the main aim of reducing the dosing frequency and prolonging the therapeutic outcomes. Thus, it is essential to select the appropriate biopolymer material, e.g., sodium alginate to formulate nanoparticles for controlled drug delivery. Alginate has attracted considerable interest in pharmaceutical and biomedical applications as a matrix material of nanocarriers due to its inherent biological properties, including good biocompatibility and biodegradability. Various techniques have been adopted to synthesize alginate nanoparticles in order to introduce more rational, coherent, efficient and cost-effective properties. This review highlights the most used and recent manufacturing techniques of alginate-based nanoparticulate delivery system, including emulsification/gelation complexation, layer-by-layer, spray drying, electrospray and electrospinning methods. Besides, the effects of the main processing and formulation parameters on alginate nanoparticles are also summarized.

As per the WHO, colorectal cancer (CRC) caused around 935,173 deaths worldwide in 2020 in both sexes and at all ages. The available anticancer therapies including chemotherapy, radiotherapy and anticancer drugs are all associated with limited therapeutic efficacy, adverse effects and low chances. This has urged to emerge several novel therapeutic agents as potential therapies for CRC including synthetic and natural materials. Orally administrable and targeted drug delivery systems are attractive strategies for CRC therapy as they minimize the side effects, enhance the efficacy of anticancer drugs. Nevertheless, oral drug delivery till today faces several challenges like poor drug solubility, stability, and permeability. Various oral nano-based approaches and targeted drug delivery systems have been developed recently, as a result of the ability of nanoparticles to control the release of the encapsulant, drug targeting and reduce the number of dosages administered. The unique physicochemical properties of chitosan polymer assist to overcome oral drug delivery barriers and target the colon tumour cells. Chitosan-based nanocarriers offered additional improvements by enhancing the stability, targeting and bioavailability of several anti-colorectal cancer agents. Modified chitosan derivatives also facilitated CRC targeting through strengthening the protection of encapsulant against acidic and enzyme degradation of gastrointestinal track (GIT). This review aims to provide an overview of CRC pathology, therapy and the barriers against oral drug delivery. It also emphasizes the role of nanotechnology in oral drug targeted delivery system and the growing interest towards chitosan and its derivatives. The present review summarizes the relevant works to date that have studied the potential applications of chitosan-based nanocarrier towards CRC treatment.

Pharmaceutical scientists have long struggled to develop reliable and efficient systems of administering insulin orally due to multiple barriers, including stomach acidity, enzymatic degradation, and mucus barriers. However, various strategies were developed to avoid insulin degradation in the gastrointestinal tract (GIT) and promote membrane permeability and biological activity. Among these strategies, chitosan polymer-based carriers are widely researched due to their ability to protect insulin in the alimentary canal and deliver it effectively through the intestinal mucosa, improving its bioavailability. To improve chitosan properties, chemical and physical modifications have been developed, and recently, nanoparticles, microparticles, and beads of chitosan exhibited potential systems for oral insulin delivery (OID). This review facilitates an outline of the types of diabetes mellitus, insulin biosynthesis, and gastrointestinal barriers against oral insulin. Moreover, the limitations of subcutaneous insulin delivery and alternative routes of administration are also discussed. As an ideal and most convenient oral administration route, the challenges of safe insulin delivery through the GIT and strategies to elevate its bioavailability are highlighted. In addition, this review focuses on recent advancements in chitosan based carriers for OID and their potential future applications.

Kidney disease management and treatment are currently causing a substantial global burden. The kidneys are the most important organs in the human urinary system, selectively filtering blood and metabolic waste into urine via the renal glomerulus. Based on charge and/or molecule size, the glomerular filtration apparatus acts as a barrier to therapeutic substances. Therefore, drug distribution to the kidneys is challenging, resulting in therapy failure in a variety of renal illnesses. Hence, different approaches to improve drug delivery across the glomerulus filtration barrier are being investigated. Nanotechnology in medicine has the potential to have a significant impact on human health, from illness prevention to diagnosis and treatment. Nanomaterials with various physicochemical properties, including size, charge, surface and shape, with unique biological attributes, such as low cytotoxicity, high cellular internalization and controllable biodistribution and pharmacokinetics, have demonstrated promising potential in renal therapy. Different types of nanosystems have been employed to deliver drugs to the kidneys. This review highlights the features of the nanomaterials, including the nanoparticles and corresponding hydrogels, in overcoming various barriers of drug delivery to the kidneys. The most common delivery sites and strategies of kidney-targeted drug delivery systems are also discussed.

Background/Objectives: Thymoquinone (TQ) exhibits diverse biological activities, but its poor solubility and bioavailability limit its cancer efficacy, requiring innovative solutions. This study explores the development of an oral delivery system targeting colon cancer based on TQ pectin beads (TQ-PBs) produced through an adjustable electrospray technique. This study hypothesised that adjusting bead diameter through the electrospray technique enables precise control over water absorption and erosion rates, thereby achieving a controlled release profile for encapsulated TQ, which enhances targeted delivery to the colon. Methods: TQ-PBs were synthesised and optimised using an electrospray technique based on the ionic gelation method. The prepared beads were characterised based on particle size, sphericity, encapsulation efficiency (EE), water uptake, erosion, surface morphology, molecular interactions, and texture. The cumulative TQ release studies, an accelerated stability test, and cytotoxicity evaluation against the colon cancer HT-29 cell line were also assessed. Results: The optimised TQ-PB formulation demonstrated an average bead size of 2.05 ± 0.14 mm, a sphericity of 0.96 ± 0.05, and an EE of 90.32 ± 1.04%. The water uptake was 287.55 ± 10.14% in simulated gastric fluid (SGF), 462.15 ± 12.73% in simulated intestinal fluid (SIF), and 772.41 ± 13.03% in simulated colonic fluid (SCF), with an erosion rate of 45.23 ± 5.22%. TQ release was minimal in SGF (8.13 ± 1.94% after 2 h), controlled in SIF (29.35 ± 3.65% after 4 h), and accelerated in SCF (94.43 ± 2.4% after 3 h). Stability studies over one month showed a size reduction of 17.50% and a 6.59% decrease in TQ content. Cytotoxicity assessments revealed significant anticancer activity of TQ-PB, with an IC50 of 80.59 ± 2.2 μg/mL. Conclusions: These findings underscore the potential of TQ-PB as an effective oral drug delivery system for targeted colorectal cancer therapy.