Reconstruction of large and complex hard tissue defects remains a major clinical challenge, as conventional autografts and allografts are often limited in availability, biological compatibility, and long-term efficacy, particularly for extensive defects or poor bone quality. Recombinant human bone morphogenetic protein-2 (rhBMP-2) is a potent osteoinductive factor capable of initiating the complete cascade of bone formation. However, its clinical use is restricted by dose-dependent complications such as inflammation, ectopic ossification, and osteolysis. This review synthesizes current evidence on the safety profile of rhBMP-2 and examines strategies to enhance its therapeutic index. Preclinical and clinical data indicate that conventional collagen-based carriers frequently cause rapid burst release and uncontrolled diffusion, aggravating adverse outcomes. It is noteworthy that low doses of rhBMP-2 (0.5–0.7 mg/level in anterior cervical discectomy and fusion (ACDF) or 0.5–1.0 mg/level in transforaminal lumbar interbody fusion (TLIF)) provide the optimal balance of efficacy and safety. Advanced biomaterial-based platforms, such as bioceramic–polymer composites, injectable hydrogels, and 3D-printed scaffolds, enable spatially and temporally controlled release while maintaining osteogenic efficacy. Molecular delivery approaches, including chemically modified messenger RNA (cmRNA) and regional gene therapy, provide transient, site-specific rhBMP-2 expression with reduced dosing and minimal systemic exposure. By integrating mechanistic insights with translational advances, this review outlines a framework for optimizing rhBMP-2-based regenerative protocols, emphasizing their potential role in multidisciplinary strategies for reconstructing complex hard tissue defects.

Pancreatic regeneration is a complex process observed in both normal and pathological conditions. The aim of this review is to provide a comprehensive understanding of the emergence of a functionally active population of insulin-secreting β-cells in the adult pancreas. The renewal of β-cells is governed by a multifaceted interaction between cellular sources of genetic and epigenetic factors. Understanding the development and heterogeneity of β-cell populations is crucial for functional β-cell regeneration. The functional mass of pancreatic β-cells increases in situations such as pregnancy and obesity. However, the specific markers of mature β-cell populations and postnatal pancreatic progenitors capable of increasing self-reproduction in these conditions remain to be elucidated. The capacity to regenerate the β-cell population through various pathways, including the proliferation of pre-existing β-cells, β-cell neogenesis, differentiation of β-cells from a population of progenitor cells, and transdifferentiation of non-β-cells into β-cells, reveals crucial molecular mechanisms for identifying cellular sources and inducers of functional cell renewal. This provides an opportunity to identify specific cellular sources and mechanisms of regeneration, which could have clinical applications in treating various pathologies, including in vitro cell-based technologies, and deepen our understanding of regeneration in different physiological conditions.

Type 2 diabetes (T2D) is a complex metabolic disorder characterized by systemic insulin resistance and progressive deterioration of pancreatic β-cell function. Advances in single-cell transcriptomics, epigenomics, and spatial transcriptomics have delineated marked β-cell heterogeneity, revealing subpopulations with differential secretory capacity, stress resilience, and vulnerability to metabolic and immune-mediated insults. These high-resolution approaches have further identified disease-associated alterations in other islet endocrine cells, as well as in immune, stromal, and exocrine pancreatic compartments, highlighting the central role of intercellular signaling in T2D pathogenesis. Concurrently, microbiome research has elucidated mechanisms by which gut microbial composition and metabolic activity modulate glucose homeostasis and β-cell function through immunoregulatory pathways, maintenance of epithelial barrier integrity, and enteroendocrine signaling, notably via glucagon-like peptide-1 (GLP-1). Therapeutic strategies targeting the gut microbiota include conventional probiotics, prebiotics, and fecal microbiota transplantation, alongside emerging synthetic biology approaches employing genetically engineered probiotic strains to deliver bioactive molecules, including GLP-1, directly in the gut microenvironment. This review integrates current multi-omics and experimental evidence to provide a comprehensive framework for understanding β-cell molecular plasticity, microbiota-mediated metabolic regulation, and their intersection as potential therapeutic targets. Such integrative approaches offer prospects for the development of precision interventions aimed at preserving or restoring β-cell function in T2D.

Regenerative medicine uses cells as therapeutic agents to heal tissues and organs. It is a rapidly evolving area of research worldwide. Cell-based therapy has emerged as a pivotal treatment approach for articular cartilage defects, recognizing the limited regenerative potential of cartilage inherent to its structural biology. Given the inherent challenges associated with the standardization of cell-based drugs compared to conventional pharmaceuticals, the evaluation of their safety and efficacy in preclinical or clinical trials incurs particular considerations. In the majority of cases, autologous chondrocytes and mesenchymal stem/stromal cells derived from various tissues become key components of cell-based therapies currently available for cartilage defects. The cell-based therapies that have been approved for clinical use vary in manufacturing methods, types of cells, and use of matrices as a cell carriers in the finished product. Furthermore, clinicians routinely use a range of surgical techniques to perform a biopsy procedure for the preparation and subsequent implantation of finished cell-based products. Each cell-based treatment option available for patients with cartilage diseases offers a particular indication, benefits, and limitations, underscoring the relevance of comparative analysis of the therapies currently used in clinical practice. This will facilitate clinicians in selecting the most suitable therapy, while researchers may potentially expand the range of diagnoses for such therapies or enhance their efficacy. This review will focus on certain cell-based therapies that have currently arrived at the stages of clinical investigation and have been approved for the treatment of cartilage defects.

Tissue-engineered constructs (TECs), the dermal equivalent (DE) and the skin equivalent (SE), are allogenic equivalents of the skin and derm used to treat critical skin loss. Selection of storage conditions that contribute to longer shelf life, thereby expanding the possibilities of logistics and use, is one of the major issues related to the TECs development. The study was aimed to determine the shelf life of the DE and SE TECs stored in normal saline at room temperature by assessing morphology and viability of the cells on their surface, along with the levels of endothelial growth factor (VEGF) secreted by these cells. Using the MTT assay and staining with vital dye, we discovered the following: when TECs of both types were stored in normal saline, the cells viability and metabolic activity decreased by more than 50% by days 3–4 of storage. Furthermore, these decreased faster in DEs than in SEs. Morphology of the cells isolated from DEs and SEs after the 3-day storage remained unchanged. Mesenchymal stem cells on the surface of TECs kept producing VEGF after TECs culture medium was changed for saline solution (confirmed by immunofluorescence assay), which could indicate that the cells retained essential secretory activity.

One of the approaches to cartilage tissue restoration problem relies on cellular technologies that use iPSCs, induced pluripotency stem cells that are an unlimited source of cellular material for tissue engineering with significant differentiation potential. However, there are no standardized protocols for chondrogenic differentiation of iPSCs. This study aimed to make cartilage tissue samples using 3D spheroid cultures and following four chondrogenic differentiation protocols, then compare characteristics of the cartilage samples made under different protocols and isolate the most effective way of differentiation. The iPSCs were differentiated chondrogenically, the four protocols were "long", "short", "combined" and with conditioned medium from a primary culture of autologous chondrocytes; the combinations of TGFβ1, BMP2, Chir 99021, and PK factors varied. Microwell plates were used to make spheroids. Immunocytochemical staining, real-time PCR and histological staining enabled assessment of the synthesis and expression profiles. High rates of synthesis and expression of chondrogenic markers Sox9, aggrecan, type II collagen were observed in spheroids experimented with under the "long", "combined" protocols and the conditioned medium protocol. The "combined" differentiation protocol made chondrogenesis most effective, and conditioned medium was highly efficient in inducing and supporting chondrogenic differentiation.