Wound repair preserves tissue integrity through four overlapping phases—hemostasis, inflammation, proliferation, and remodeling—coordinated by platelets, neutrophils, macrophages, fibroblasts, keratinocytes, endothelial cells, and stem/progenitor cells acting with growth factors, chemokines, extracellular matrix, and intracellular signaling. Disruption of these programs results in chronic non-healing wounds or fibrotic scarring. Recent work delineates microbial influences, epigenetic and transcriptomic regulation, and cellular heterogeneity resolved by single-cell and spatial omics. Concurrent advances in biomaterials, engineered scaffolds, stem cell-derived products, and genome-targeted approaches are enabling mechanism-based therapies. Persistent challenges include wound heterogeneity, systemic modifiers such as diabetes and aging, and safe, effective delivery of biologics. This review summarizes cellular and molecular mechanisms of cutaneous repair, outlines deviations that underlie pathological healing, and evaluates emerging concepts and translational strategies. Integrating classical models with contemporary insights supports the development of precision wound medicine and personalized interventions to improve outcomes and quality of life.

Fibrous dysplasia (FD) is a rare, non-hereditary skeletal disorder characterized by its chronic course of non-neoplastic fibrous tissue buildup in place of healthy bone. A myriad of factors have been associated with its onset and progression. Perturbation of cell–cell signaling networks and response outputs leading to disrupted building blocks, incoherent multi-level organization, and loss of rigid structural motifs in mineralized tissues are factors that have been identified to participate in FD induction. In more recent years, novel insights into the unique biology of FD are transforming our understandings of its pathology, natural discourse of the disease, and treatment prospects. Herein, we built upon existing knowledge with recent findings to review clinical, etiologic, and histological features of FD and discussed known and potential mechanisms underlying FD manifestations. Subsequently, we ended on a note of optimism by highlighting emerging therapeutic approaches aimed at either halting or ameliorating disease progression.

Background: Polydioxanone (PDO) threads, poly‐L‐lactic acid (PLLA) threads, and polycaprolactone (PCL) threads have been used for lifting and antiaging purposes. The new PCL threads that have less residual monomer compared to the previous PCL are developed.Aims: The efficacy of threads regarding collagen synthesis and wrinkle improvement was evaluated in vivo model.Methods: In this study, threads were inserted into 30 six‐week‐old male SKH‐1 hairless mice. One of four threads was implanted at either side of the spine of each mouse. Biopsy specimens obtained at 1, 4, and 8 weeks were examined using hematoxylin and eosin (H&E) and Herovici's stain. Additionally, immunoblot analysis was performed using primary antibody for collagen type III and transforming growth factor‐β (TGF‐β) and visualized by chemiluminescence and densitometric quantification. Finally, skin replicas were used to calculate total wrinkle area (mm²).Results: Neocollagenesis was significantly increased by 50% in the new PCL and pre‐existing PCL groups at 8 weeks (p value < 0.001). Additionally, new‐PCL‐implanted mice showed a significant increase in collagen type III and TGF‐β expressions at 8 weeks (p value < 0.001). The number of inflammatory cells was also increased in the skin of PCL‐implanted mice at 8 weeks. Finally, wrinkles were reduced about 20% in the new PCL group at 8 weeks.Conclusions: The new PCL thread exhibited a superior skin rejuvenation effect. This suggests that the material processing technology can be applied not only to the thread but also to various products such as dermal filler and cosmetics.

The number of breast reconstruction surgeries has been increasing due to the increase in mastectomies. Surgical implants (the standard polydimethylsiloxane (PDMS) implants) are widely used to reconstruct breast tissues, however, it can cause problems such as adverse immune reactions, fibrosis, rupture, and additional surgery. Hence, polymeric fillers have recently garnered increasing attention as strong alternatives for breast reconstruction materials. Polymeric fillers offer noninvasive methods of reconstruction, thereby reducing the possible adverse effects and simplifying the treatment. In this study, we synthesized a 2-hydroxylethylmethacrylate (HEMA) and acrylamide (Am) copolymer (Poly(HEMA-Am)) by redox polymerization to be used as a biocompatible filler material for breast reconstruction. The synthesized hydrogel swelled in phosphate buffered saline (PBS) shows an average modulus of 50 Pa, which is a characteristic similar to that of the standard dermal acrylamide filler. To investigate the biocompatibility and cytotoxicity of the Poly(HEMA-Am) hydrogel, we evaluated an in vitro cytotoxicity assay on human fibroblasts (hFBs) and human adipose-derived stem cells (hADSCs) with the hydrogel eluate, and confirmed a cell viability of over 80% of the cell viability with the Poly(HEMA-Am) hydrogel. These results suggest our polymeric hydrogel is a promising filler material in soft tissue augmentation including breast reconstruction.

Melanoma is visible unlike other types of cancer, but it is still challenging to diagnose correctly because of the difficulty in distinguishing between benign nevus and melanoma. We conducted a robust investigation of melanoma, identifying considerable differences in local elastic properties between nevus and melanoma tissues by using atomic force microscopy (AFM) indentation of histological specimens. Specifically, the histograms of the elastic modulus of melanoma displayed multimodal Gaussian distributions, exhibiting heterogeneous mechanical properties, in contrast with the unimodal distributions of elastic modulus in the benign nevus. We identified this notable signature was consistent regardless of blotch incidence by sex, age, anatomical site (e.g., thigh, calf, arm, eyelid, and cheek), or cancer stage (I, IV, and V). In addition, we found that the non-linearity of the force-distance curves for melanoma is increased compared to benign nevus. We believe that AFM indentation of histological specimens may technically complement conventional histopathological analysis for earlier and more precise melanoma detection.

With the aging population, there is a rising incidence of senile diseases, notably osteoporosis, marked by fractures, prolonged recovery, and elevated mortality rates, underscoring the urgency for effective treatments. In this study, we applied the method of absorbing parathyroid hormone (PTH), a treatment for osteoporosis, into graft materials. Two types of graft materials with different properties, whitlockite (WH) and hydroxyapatite (HAP), were used. After forming calvarial defects in osteoporotic rats, WH and HAP grafts were implanted, with PTH applied directly to the graft sites. Micro-CT analysis was employed to assess bone regeneration, while tissue sections were stained to elucidate the regeneration process and bone cell dynamics. The results showed that bone regeneration was higher in the grafts that were actively degraded by osteoclasts in the early stage of regeneration. When PTH was applied, osteoclast activity increased, leading to enhanced bone regeneration. Furthermore, the activation of osteoclasts resulted in the penetration and formation of new bone within the degraded graft, which exhibited higher osseointegration. Therefore, for osteoporotic bone defects, bone grafts that can be easily degraded by osteoclasts are more suitable. Additionally, treatment with PTH can activate osteoclasts around the bone graft in the early stages of regeneration, inducing higher bone regeneration and improving osseointegration.