Zinc is known for its role in enhancing bone metabolism, cell proliferation, and tissue regeneration. Several studies proposed the incorporation of zinc into hydroxyapatite (HA) to produce biomaterials (ZnHA) that stimulate and accelerate bone healing. This systematic review aimed to understand the physicochemical characteristics of zinc-doped HA-based biomaterials and the evidence of their biological effects on osteoblastic cells. A comprehensive literature search was conducted from 2022 to 2024, covering all years of publications, in three databases (Web of Science, PUBMED, Scopus), retrieving 609 entries, with 36 articles included in the analysis according to the selection criteria. The selected studies provided data on the material’s physicochemical properties, the methods of zinc incorporation, and the biological effects of ZnHA on bone cells. The production of ZnHA typically involves the wet chemical synthesis of HA and ZnHA precursors, followed by deposition on substrates using processes such as liquid precursor plasma spraying (LPPS). Characterization techniques confirmed the successful incorporation of zinc into the HA lattice. The findings indicated that zinc incorporation into HA at low concentrations is non-cytotoxic and beneficial for bone cells. ZnHA was found to stimulate cell proliferation, adhesion, and the production of osteogenic factors, thereby promoting in vitro mineralization. However, the optimal zinc concentration for the desired effects varied across studies, making it challenging to establish a standardized concentration. ZnHA materials are biocompatible and enhance osteoblast proliferation and differentiation. However, the mechanisms of zinc release and the ideal concentrations for optimal tissue regeneration require further investigation. Standardizing these parameters is essential for the effective clinical application of ZnHA.

“Unusual sporotrichosis”, a concept proposed in this review, refers to severe, extracutaneous, or anatomically atypical manifestations of sporotrichosis occurring in immunocompetent hosts and represents an underrecognized clinical subset associated with important diagnostic and therapeutic challenges. This systematic review aimed to characterize unusual sporotrichosis worldwide and to clarify its epidemiological, clinical, diagnostic, and therapeutic patterns. Following a registered protocol and PRISMA guidelines, PubMed, Scopus, and BVS/LILACS were searched up to November 2025 using a PICO-based strategy. Eligible studies included peer-reviewed case reports and case series with laboratory-confirmed sporotrichosis in patients without immunosuppression, diabetes mellitus, alcoholism, or other confounding comorbidities; classical lymphocutaneous and fixed cutaneous forms were excluded. From 922 records, 39 studies were included (13 case series and 26 case reports), yielding 55 cases reported between 1957 and 2024 across five world regions, mainly from the United States of America and Brazil. Adults aged 40–59 years (41.8%) and males (74.5%) predominated. Sapronotic transmission was most frequent (69.0%), although zoonotic transmission increased over time. Sporothrix schenckii/Sporothrix schenckii sensu stricto was the predominant species (87.3%). Osteoarticular (30.9%) and systemic (27.2%) forms were the most common presentations. Although cure was achieved in most cases (58.1%), sequelae were frequent (21.8%), and the worst prognosis—including most deaths—was observed in osteoarticular sporotrichosis. Unusual sporotrichosis is globally distributed and clinically distinct; therefore, early recognition and multimodal diagnostic and therapeutic strategies are essential to improve outcome.

The increasing demand for effective bone regeneration materials drives the exploration of biomaterials with enhanced bioactivity and biocompatibility, such as zinc-substituted compounds. This study investigates the in vitro cellular interactions with nanostructured spheres composed of alginate/carbonated hydroxyapatite (CHA), compared to zinc-substituted CHA (ZnCHA). This work aimed to compare the physicochemical properties and biological effects of ZnCHA and CHA on osteoblasts. ZnCHA was synthesized using a wet chemical method, followed by characterization through X-ray diffraction, Fourier transform infrared spectroscopy, total organic carbon analysis, Wavelength-dispersive X-ray spectroscopy, and BET surface area analysis to assess ion release and structural changes. Biological evaluation was conducted using cell viability, proliferation, and biomineralization assays on osteoblasts. Results showed successful incorporation of zinc and carbonate, leading to reduced crystallinity and increased surface area. Cell viability and proliferation assays indicated ZnCHA’s cytocompatibility and enhanced osteoblastic activity, with increased mineralization nodules compared to CHA samples. The study concludes that ZnCHA composites are promising candidates for bone tissue engineering, demonstrating improved cytocompatibility and potential for further preclinical evaluations.