Sentinel lymph node biopsy (SLNB) is a surgical procedure that has been used in patients with cutaneous melanoma for nearly 30 years. It is used for both staging and regional disease control with minimum morbidity, as proven by numerous worldwide prospective studies. It has been incorporated in the recommendations of national and professional guidelines. In this article, we provide a summary of the general information on SLNB in the clinical guidelines for the management of cutaneous malignant melanoma (American Association of Dermatology, European Society of Medical Oncology, National Comprehensive Cancer Network, and Cancer Council Australia) and review the most relevant literature to provide an update on the existing recommendations for SLNB.

Both cutaneous melanoma (CM) and uveal melanoma (UM) represent important causes of morbidity and mortality. In this review, we evaluate the available knowledge on the differences and similarities between cutaneous melanoma and uveal melanoma, focusing on the epidemiological aspects and risk factors. Uveal melanoma is a rare condition but is the most prevalent primary intra-ocular malignant tumor in adults. Cutaneous melanoma, on the other hand, is significantly more common. While the frequency of cutaneous melanoma has increased in the last decades worldwide, the incidence of uveal melanoma has remained stable. Although both tumors arise from melanocytes, they are very distinct entities biologically, with complex and varied etiologies. Both conditions are encountered more frequently by individuals with a fair phenotype. ultraviolet-radiation is an important, well-documented risk factor for the development of CM, but has shown not to be of specific risk in UM. Although cutaneous and ocular melanomas seem to be inherited independently, there are reported cases of concomitant primary tumors in the same patient.

Fractures are becoming a bigger and bigger global health problem, with an estimated 178 million new cases each year and 455 million people living with disabilities caused by fractures. Donor site morbidity, the risk of immune rejection, and limited functional integration all make current grafting techniques less effective. Biomaterials that come from nature, like collagen, gelatin, chitosan, alginate, hyaluronic acid (HA), and silk fibroin, have become promising scaffolds because they are bioactive, mimic the extracellular matrix (ECM), and can be broken down by enzymes. Crosslinking and composite reinforcement can greatly change how well they work. For example, collagen scaffolds that are highly crosslinked with glutaraldehyde keep up to 51.9% of their tensile strength after being exposed to enzymes, while non-crosslinked scaffolds only keep 12% of their strength. Chitosan–hydroxyapatite matrices, on the other hand, can reach compressive strengths of 2–12 MPa, which is close to the strength of cancellous bone. Additive manufacturing and 4D printing allow for precise control of structures and the ability to change their shape over time, which helps with vascularization and mechanical adaptation. Injectable and in situ-forming hydrogels show clinically important results, such as filling 85% of osteochondral defects in rabbits, improving left ventricular ejection fraction by up to 9% in large-animal cardiac models, and speeding up healing by 25–40% in chronic wounds. Even with these improvements, it is still hard to get batch consistency, a standardized way to test mechanical properties, and production that meets GMP (Good Manufacturing Practices) standards and can be scaled up.

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.