Although mesenchymal stem cells are used in numerous clinical trials, the safety of their application is still a matter of concern. We have analysed the clinical results of the autologous adipose‐derived stem cell treatment (stromal vascular fraction (SVF) containing adipose‐derived stem cells, endothelial progenitors, and blood mononuclear cells) for orthopedic (cartilage, bone, tendon, or combined joint injuries) and neurologic (multiple sclerosis) diseases. Methods of adipose tissue collection, cell isolation and purification, and resulting cell numbers, viability, and morphology were considered, and patient’s age, sex, disease type, and method of cell administration (cell numbers per single application, treatment numbers and frequency, and methods of cell implantation) were analysed and searched for the unwanted clinical effects. Results of cellular therapy were compared retrospectively to those obtained with conventional medication without SVF application. SVF transplantation was always the accessory treatment of patients receiving “standard routine” therapies of their diseases. Clinical experiments were approved by the Bioethical Medical Committees supervising the centers where patients were hospitalised. The conclusion of the study is that none of the treated patients developed any serious adverse event, and autologous mesenchymal stem (stromal) cell clinical application is a safe procedure resulting in some beneficial clinical effects (not analysed in this study).

The aim was to examine the efficiency of a scaffold made of poly (L-lactic acid)-co-poly(ϵ-caprolactone), collagen (COL), polyaniline (PANI), and enriched with adipose-derived stem cells (ASCs) as a nerve conduit in a rat model. P(LLA-CL)-COL-PANI scaffold was optimized and electrospun into a tubular-shaped structure. Adipose tissue from 10 Lewis rats was harvested for ASCs culture. A total of 28 inbred male Lewis rats underwent sciatic nerve transection and excision of a 10 mm nerve trunk fragment. In Group A, the nerve gap remained untouched; in Group B, an excised trunk was used as an autograft; in Group C, nerve stumps were secured with P(LLA-CL)-COL-PANI conduit; in Group D, P(LLA-CL)-COL-PANI conduit was enriched with ASCs. After 6 months of observation, rats were sacrificed. Gastrocnemius muscles and sciatic nerves were harvested for weight, histology analysis, and nerve fiber count analyses. Group A showed advanced atrophy of the muscle, and each intervention (B, C, D) prevented muscle mass decrease (p < 0.0001); however, ASCs addition decreased efficiency vs. autograft (p < 0.05). Nerve fiber count revealed a superior effect in the nerve fiber density observed in the groups with the use of conduit (D vs. B p < 0.0001, C vs. B p < 0.001). P(LLA-CL)-COL-PANI conduits with ASCs showed promising results in managing nerve gap by decreasing muscle atrophy.

3D bioprinting has become a valuable tool for studying the biology of solid tumors, including glioblastoma multiforme (GBM). Our analysis of publicly available bulk RNA and single-cell sequencing data has allowed us to define the chemotactic profile of GBM tumors and identify the cell types that secrete particular chemokines in the GBM tumor microenvironment (TME). Our findings indicate that primary GBM tissues express multiple chemokines, whereas spherical monocultures of GBM cells significantly lose this diversity. Subsequently, the comparative analysis of GBM spherical monocultures vs. 3D-bioprinted multicultures of cells showed a restoration of chemokine profile diversity in 3D-bioprinted cultures. Furthermore, single-cell RNA-Seq analysis showed that cells of the perivascular niche (pericytes and endocytes) express multiple chemokines in the GBM TME. Next, we 3D-bioprinted cells from two glioblastoma cell lines, U-251 and DK-MG, alone and as co-cultures with mesenchymal stromal cells (representing cells of the perivascular niche) and assessed the chemokine secretome. The results clearly demonstrated that the interaction of tumors and mesenchymal cells leads to in a significant increase in the repertoire and levels of secreted chemokines under culture in 21% O₂ and 1% O₂. Our study indicates that cells of the perivascular niche may perform a substantial role in shaping the chemokine microenvironment in GBM tumors.

The P19 cell line derived from a mouse embryo-derived teratocarcinoma has the ability to differentiate into the three germ layers. In the presence of retinoic acid (RA), the suspension cultured P19 cell line is induced to differentiate into neurons. This phenomenon is extensively investigated as a neurogenesis model in vitro. Therefore, the P19 cell line is very useful for molecular and cellular studies associated with neurogenesis. However, protocols for neuronal differentiation of P19 cell line described in the literature are very complex. The method developed in this study are simple and will play a part in elucidating the molecular mechanisms in neurodevelopmental abnormalities and neurodegenerative diseases.

The development of tissue-engineered scaffolds with electrical properties is the primary motivation of novel regenerative medicine. Electroconductive scaffolds are designed to mimic the injured tissue environment's electrical properties and regulate cellular behavior - growth, proliferation, and differentiation - that could stimulate the injured nerve's regeneration. We fabricated dedicated electroconductive scaffolds and customized an appropriate device with an external current supply to expose cells on the scaffold to electrical stimulation (ES). Next, we isolated rat adipose-derived stem cells (ASCs) and performed in vitro experiments that combine cells, an electroconductive scaffold, NGF (nerve growth factor), and ES (90 mV/mm, constant, for four days). Finally, we checked cellular activity as proliferation, viability, morphology, the neurogenic differentiation potential of ASCs, cell alignment, and karyotype. We observed that the electrical stimulation did not change the viability and chromosome stability of rat ASCs, but altered slightly proliferation compared to non-stimulated cells. The combined effect of a scaffold, NGF, and ES caused morphology changes and enhancement of ASCs neuronal differentiation as indicated in βIII-tubulin expression, actin organization, and upregulation of neurogenic gene expression. We developed an electroconductive scaffold and customized device for in vitro study with many experimental variants. Based on our results, we presumed that the established study scheme - including an electroconductive scaffold, NGF and ES - is biocompatible and could guide ASCs to differentiate in neurogenic lineage, thus may be potentially applied in nerve injury regeneration.

Extracellular vesicles (EVs) are increasingly being investigated as cell-free therapies for neurological diseases. However, their clinical application remains limited by biological and functional heterogeneity. EVs should therefore not be considered as a single, uniform therapeutic product defined only by their cell of origin, size, or conventional vesicle classification. EV composition and activity are influenced by extrinsic factors, including donor and tissue source, culture conditions, and isolation procedures, as well as by intrinsic mechanisms of vesicle biogenesis and selective cargo loading. Some vesicles may have beneficial therapeutic effects, whereas others may show little biological activity or act on unintended cellular targets. For this reason, EVs may be better classified according to biological function rather than only physical properties or cellular origin. A functionality-based classification could improve potency assessment, dose selection, reproducibility, and the development of consistent EV-based products. EV properties can be modulated by selecting appropriate parental cells, modifying culture conditions, or using genetic or metabolic engineering to alter EV production and cargo. Single-vesicle approaches can reveal differences between EV subpopulations and identify those responsible for specific biological effects. Overall, understanding EV heterogeneity may provide a rational basis for developing reproducible and disease-specific EV therapies for neurological and neurodegenerative disorders.