Research on in vitro skin models has advanced remarkably, driven by a better understanding of the skin and the search for more ethical and efficient methods. The development of these models was initially motivated by the need for reduced animal testing and a faster and more ethical approach for the safety evaluation of cosmetic and pharmaceutical products. Stricter regulations and growing ethical awareness have driven further evolution, resulting in more refined and reliable methods. Diversity of cell types is crucial to replicating the complexity of human skin, including epithelial, dendritic, endothelial, and adipose cells, providing environments that closely mimic the physiological skin environment. This allows for more precise studies on skin interactions with cosmetic, dermatological, and pharmaceutical products. In vitro skin models have applications in toxicity testing, dermatological product evaluation, skin ageing studies, and drug research, reducing dependence on animal testing. This review presents a look at the different types of in vitro skin models developed for various applications, with a brief look at their strengths and drawbacks. Models developed for disease-specific applications are also covered. Techniques such as bioprinting and organ-on-a-chip have revolutionised the manufacturing of these models. Challenges persist, such as the need to improve vascularisation and faithfully replicate skin architecture. The promising future of these models points to an exciting path forward for dermatological research and the cosmetic industry. This review addresses the history and regulations of skin models, explores various skin models, and highlights the most recent advances, outlining future perspectives and offering a comprehensive overview.

Hypotelus Erichson is a genus of minute rove beetles widely distributed in Central and South America. The species were recently revised and the monophyly of the genus was confirmed based on morphological data. We describe a new species from Ecuador, provide scanning electron microscope images to demonstrate the diagnostic characteristics of the genus and include the new species in a dichotomous key. We also reassess the monophyly of the genus, now including the new species, using morphological and molecular data combined. Hypotelus chusqueaticus sp. nov. is similar to H. testaceus, but differs by having elytra unicolored, male sternite 8 with posterior margin somewhat pointed and female sternite 8 with posterior margin projected in middle-third. Including the new species, Hypotelus is confirmed as a monophyletic group with three internal clades. The new species is closely related to H. marginatus.