(1) Background: This review study will delve into the potential of chitosan nanoparticles (NPs) as adaptable carriers for targeted drug delivery in different therapeutic areas. Chitosan is a biopolymer derived from chitin that has attracted interest in drug delivery applications because of its high biocompatibility and biodegradability. (2) Methods: A comprehensive literature review was conducted by following a careful systematized protocol for searching databases like PubMed, Google Scholar and ScienceDirect. (3) Results: Chitosan NPs are good drug delivery vehicles, notably for cancer. Studies reveal that doxorubicin-loaded chitosan NPs dramatically enhance toxicity to tumor cells compared to free medicines, yielding tumor suppression rates of up to 60%. Researchers found that chemotherapeutics had an 85% encapsulation efficiency (EE), lowering systemic toxicity. Magnetic and pH-responsive chitosan NPs boost drug accumulation by 63% and apoptosis by 54%. Chitosan also boosts medication retention in the lungs by 2.3×, per pulmonary delivery trials. Chitosan NPs also boost ocular medication bioavailability by 3× and improve nasal absorption by 30%, crossing the blood–brain barrier. For bone regeneration, chitosan scaffolds enhance bone mineral density by 46%, facilitating osteogenesis and healing. (4) Conclusions: NPs made of chitosan provide a solid foundation for improving drug delivery systems; yet there are still issues with material variability, scalability, and meeting regulatory requirements that need fixing. Research into combination treatments, ways to increase their specificity, and ways to optimize these NPs offers promising prospects for the creation of novel therapeutic approaches with the potential to improve patient outcomes.

According to the World Health Organization, musculoskeletal injuries affect more than 1.71 billion people around the world. These injuries are a major public health issue and the leading cause of disability. There has been a recent interest in hydrogels as a potential biomaterial for musculoskeletal tissue regeneration. This is due to their high water content (70–99%), ECM-like structure, injectability, and controllable degradation rates. Recent preclinical studies indicate that they can enhance regeneration by modulating the release of bioactive compounds, growth factors, and stem cells. Composite hydrogels that combine natural and synthetic polymers, like chitosan and collagen, have compressive moduli that are advantageous for tendon–bone healing. Some of these hydrogels can even hold up to 0.8 MPa of tensile strength. In osteoarthritis models, functionalized systems such as microspheres responsive to matrix metalloproteinase-13 have demonstrated disease modulation and targeted drug delivery, while intelligent in situ hydrogels have exhibited a 43% increase in neovascularization and a 50% enhancement in myotube production. Hydrogel-based therapies have been shown to restore contractile force by as much as 80%, increase myofiber density by 65%, and boost ALP activity in bone defects by 2.1 times in volumetric muscle loss (VML) models. Adding TGF-β3 or MSCs to hydrogel systems improved GAG content by about 60%, collagen II expression by 35–50%, and O’Driscoll scores by 35–50% in cartilage regeneration.