Treatment for delayed wound healing resulting from peripheral vascular diseases and diabetic foot ulcers remain a challenge. A novel surgical technique named Tibial Cortex Transverse Transport has been developed for treating peripheral ischaemia, with encouraging clinical effects. However, its underlying mechanisms remain unclear. In present study, we aimed to explore the wound healing effects after undergoing this novel technique via multiple ways. A novel rat model of Tibial Cortex Transverse Transport was established with a designed external fixator and effects on wound healing were investigated. All rats were randomized into 3 groups, with 12 rats per group: sham group (negative control), fixator group (positive control) and Tibial Cortex Transverse Transport group. Laser speckle perfusion imaging, vessel perfusion, histology and immunohistochemistry were used to evaluate the wound healing processes. Gross and histological examinations showed that Tibial Cortex Transverse Transport technique accelerated wound closure and enhanced the quality of the newly formed skin tissues. In Tibial Cortex Transverse Transport group, HE staining demonstrated a better epidermis and dermis recovery, while immune-histochemical staining showed that Tibial Cortex Transverse Transport technique promoted local collagen deposition. Tibial Cortex Transverse Transport technique also benefited to angiogenesis and immunomodulation. In Tibial Cortex Transverse Transport group, blood flow in the wound area was higher than that ofother groups according to laser speckle imaging with more blood vessels observed. Enhanced neovascularization was seen in the Tibial Cortex Transverse Transport group with double immune-labelling of CD31 and α-SMA. The M2 macrophages at the wound site in the Tibial Cortex Transverse Transport group was also increased. Tibial cortex transverse transport technique accelerated wound healing through enhanced angiogenesis and immunomodulation

Introduction. Femoral head osteonecrosis (FHO) is a condition in which the inadequate blood supply disrupts osteogenic-angiogenic coupling that results in diminishment of femoral perfusion and ends up with FHO. The insufficient knowledge on molecular background and progression pattern of FHO and the restrictions in obtaining human samples bring out the need for a small animal trauma model to research FHO aetiology. Hence, this study aims to develop a mouse trauma model to elucidate the molecular mechanisms behind FHO. Method. Left femoral head was dislocated from the hip joint, ligamentum teres was cut, and a slight circular incision was done around the femoral neck of 8-week-old male C57BL/6J mice to disrupt the blood supply to femoral head. Right hip joint was left unoperated as control. Animals (n=5 per time point) were sacrificed on 2-3-4-6-8-10-12 weeks, and ex-vivo µCT was taken to assess bone structural parameters. Haematoxylin/eosin (HE)- and immunohistochemical-staining (IHCS) for CD31 and EMCN were done to observe histology and marrow-specific H-type vascular structures, respectively. Result. μCT assessment showed trabecular bone loss and decreased BV/TV from 2 to 8 weeks in FHO side. HE staining displayed the increased number of empty lacunae was observed in FHO side as early as 24h after operation. By 4. th. week, IHCS results displayed the invasion of the epiphyseal plate by H-type blood vessels in FHO side, while the epiphyseal plate was observed intact in control side. Also, by 6. th. week the HE-staining showed the presence of bone marrow necrosis and bone fat accumulation in FHO side. Conclusion. Trabecular bone loss, increased number of empty lacunae, bone fat imbalance and bone marrow necrosis are reported as the signs of osteonecrosis. Thus, our results are coherent with the literature and indicated that we were able to effectively generate a trauma model for FHO in mice for the first time in literature

In this work, we combined tissue engineering and gene therapy technologies to develop a therapeutic platform for bone regeneration. We have developed photothermal fibrin-based hydrogels that incorporate degradable CuS nanoparticles (CuSNP) which transduce incident near-infrared (NIR) light into heat. A heat-activated and rapamycin-dependent transgene expression system was incorporated into mesenchymal stem cells to conditionally control the production of bone morphogenetic protein 2 (BMP-2). Genetically engineered cells were entrapped in the photothermal hydrogels. In the presence of rapamycin, photoinduced mild hyperthermia induced the release of BMP-2 from the NIR responsive cell constructs. Transcriptome analysis of BMP-2 expressing cells showed a signature of induced genes related to stem cell proliferation and angiogenesis. We next generated 4 mm diameter calvarial defects in the left parietal bone of immunocompetent mice. The defects were filled with NIR-responsive hydrogels entrapping cells that expressed BMP-2 under the control of the gene circuit. After one and eight days, rapamycin was administered intraperitoneally followed by irradiation with an NIR laser. Ten weeks after implantation, the animals were euthanized and samples from the bone defect zone were processed for histological analysis using Masson's trichrome staining and for immunohistochemistry analyses using specific CD31 and CD105 antibodies. Samples from mice that were only administered rapamycin or vehicle or that were only NIR-irradiated showed the persistence of fibrous tissue bridging the defect. In animals that were treated with rapamycin, NIR irradiation of implants resulted in the formation of new mineralized tissue with a high degree of vascularization, thus indicating the therapeutic potential of the approach. Acknowledgements: This research was supported by grants RTI2018-095159-B-I00 and PID2021-126325OB-I00 (MCIN/AEI/10.13039/501100011033 and “ERDF A way of making Europe”), by grant P2022/BMD- 7406 (Regional Government of Madrid). M.A.L-J. is the recipient of predoctoral fellowship PRE2019-090430 (MCIN/AEI/10.13039/501100011033)

Deriving autologous mesenchymal stem cells (MSCs) from adipose tissues without using enzymes requires sophisticated biomedical instruments. Applied pressure on tissues and cells are adjusted manually although centrifugation and filtration systems are frequently used. The number of derived MSCs therefore could differ between instruments. We compared the number of MSCs obtained from four commercially available devices and our newly designed and produced instrument (A2, B3, L3, M2 and T3). Three-hundred mL of adipose tissue was obtained from a female patient undergoing liposuction using the transillumination solution. Obtained tissue was equally distributed to each device and handled according to the producers' guides. After handling, 3 mL stromal vascular fraction (SVF) was obtained from each device. Freshly isolated SVF was characterized using multi-color flow cytometry (Navios Flow Cytometer, Beckman Coulter, USA). Cell surface antigens were chosen according to IFATS and ISCT. CD31-FITC, CD34-PC5,5, CD73-PE, CD90-PB and CD45-A750 (Backman Coulter, USA) fluorochrome-labeled monoclonal antibodies were assessed. Markers were combined with ViaKrome (Beckman Coulter, USA) to determine cell viability. At least 10. 5. cells were acquired from each sample. A software (Navios EX, Beckman Coulter, USA) was used to create dot plots and to calculate the cell composition percentages. The data was analyzed in the Kaluza 2.1 software package (Beckman Coulter, USA). Graphs were prepared in GraphPad Prism. CD105 PC7/CD31 FITC cell percentages were 23,9%, 13,5%, 24,6%, 11,4% and 28,8% for the A2, B3, L3, M2 and T3 devices, respectively. We conclude that the isolated MSC percentage ranged from 11,4% to 28,8% between devices. The number of MSCs in SVF are key determinants of success in orthobiological treatments. Developing a device should focus on increasing the number of MSCs in the SVF while preserving its metabolic activity. Acknowledgments: Scientific and Technological Research Council of Türkiye (TÜBİTAK)- Technology and Innovation Funding Program Directorate (TEYDEB) funded this project (#321893). Servet Kürümoğlu and Bariscan Önder of Disposet Ltd., Ankara, Türkiye (. www.disposet.com. ) contributed to the industrial design and research studies. Ali Tuncel and Feza Korkusuz are members of the Turkish Academy of Sciences (TÜBA). Nilsu Baysal was funded by the STAR Program of TÜBITAK Grant # 3210893

We studied bone-tendon healing using immunohistochemical methods in a rabbit model. Reconstruction of the anterior cruciate ligament was undertaken using semitendinosus tendon in 20 rabbits. Immunohistochemical evaluations were performed at one, two, four and eight weeks after the operation. The expression of CD31, RAM-11, VEGF, b-FGF, S-100 protein and collagen I, II and III in the bone-tendon interface was very similar to that in the endochondral ossification. Some of the type-III collagen in the outer layer of the graft, which was deposited at a very early phase after the operation, was believed to have matured into Sharpey-like fibres. However, remodelling of the tendon grafted into the bone tunnel was significantly delayed when compared with this ossification process. To promote healing, we believe that it is necessary to accelerate remodelling of the tendon, simultaneously with the augmentation of the ossification

Introduction and Objective. The use of microfragmented adipose tissue (mFAT) for the treatment of musculoskeletal disorders, especially osteoarthritis, is gaining popularity following the positive results reported in recent case series and clinical trials. The purpose of this study is to characterize mFAT in terms of structure, cell content and secretome (i.e. protein and microvescicles released as paracrine mediators), and to compare it with unprocessed lipoaspirate tissue, in order to understand the possible mechanisms of action and the benefit derived from tissue processing. Materials and Methods. Unprocessed lipoaspirate (LA) and mFAT were obtained from 7 donors. Each tissue sample was divided in four aliquots: A) fixed in formalin for histological evaluation; B) enzymatically digested to harvest cells with the exclusion of adipocytes; C) cultured for 24 hours in serum-free DMEM to harvest secretome; D) freshly frozen for proteomic evaluation. Hematoxylin and eosin staning, as well as immunohistochemistry for CD31, CD90, CD146 were performed on aliquot A. Cell count, viability, senescence and immunophenotype were assessed on aliquot B. Culture medium from aliquot C was collected and used for proteomic analysis and micro-RNA extraction and quantitation from extracellular vesicles. Aliquot D was lysed, protein were extracted and analyzed using a high-throughput proteomic approach. Results. Histological investigations showed a lower red blood cell content in mFAT with respect to LA, while the presence of blood vessels (CD31+), stromal cells (CD90) and pericytes (CD146) was similar in all samples. These results were confirmed by flow cytometry, with reduction of erythrocytes (CD235a+) by 76% and reduction of lymphocytes (CD45+) by 79% in mFAT compared to LA. Otherwise, the proportions of stromal cells, pericytes and endothelial cells in LA and mFAT remained comparable. The percentage of senescent cells resulted similar before and after tissue processing, with very low values (< 5%). The analysis of the miRNAs contained in the extracellular vesicles in culture media identified 376 miRNAs in LA secretome and 381 in mFAT secretome. A high correlation in the expression of these miRNAs within subjects (LA and mFAT of each donor) was observed (R2> 0.8), indicating that processing in mFAT does not significantly alter the portfolio of miRNAs associated with extracellular vesicles. Proteomic analysis of secretome revealed that 217 proteins significantly differ between LA and mFAT. In particular, protein associated with acute phase were less represented in mFAT secretome, while intracellular proteins were more frequent. Proteomic analysis of tissues demonstrated a reduction of protein related to extracellular matrix and of proteins closely related to peripheral blood contamination in mFAT with respect to LA. Conclusions. Taken together, these results suggest that processing of LA into mFAT allow for removal of blood elements, in terms of red blood cells, lymphocytes, acute phase and complement system proteins, and for the reduction of extracellular matrix components. Otherwise, tissue structure, cell populations, cell viability and senescence are not influenced by tissue processing. Then, microfragmentation process represents a safe and efficient method for the application of adipose tissue properties to musculoskeletal disorders, allowing for the maintenance of all the effector elements for tissue regeneration while removing possible detrimental agents such as inflammatory mediators

Angiogenesis and the ability to provide appropriate vascular supply are crucial for skeletal tissue engineering. The aim of this study was to investigate the angiogenic potential of human dental pulp stromal cells (HDPSCs) and stro-1 positive populations as well as their role in tissue regeneration (the clinical reality). HDPSC were isolated from the pulp tissues of human permanent teeth by collagenase digestion. STRO-1 positive cells were enriched using monoclonal anti- STRO-1 and anti- CD45 PE conjugated antibodies together with and fluorescence activated cell sorting (FACS). Cells isolated by FACS were grown to passage4 and cultured as monolayers or on 3D Matrigel scaffold in endothelial cell growth medium-2 (EGM-2) with/without 50ng/mL of vascular endothelial growth factor (VEGF). Cells cultured in alpha MEM supplemented with 10% FCS were used as controls. After 24, 48 and 72 hours angiogenic marker expression (CD31, CD34, vWF and VEGFR-2) was determined by qRT-PCR and immuno-histochemistry. Using three different donors, 0.5-1.5% of total HDPSCs population was characterized as STRO-1+/CD45- cells At each time point cells cultured as monolayer in EGM-2 with VEGF showed up regulation of CD31 and VEGFR-2 expression compared to the control group while expression of CD34 and vWF remained unaffected. However on Matrigel, all four genes were up regulated to different extents. CD31 and VEGFR-2 were up regulated to a greater degree compared to CD34 and vWF. Changes in gene expression in both cell types were time dependent. Immuno-histochemical staining confirmed that the HDPSCs cultured in the test group showed positive staining for the four angiogenic markers (CD31, CD34 vWF and VEGFR-2) when grown in both monolayer and 3D Matrigel culture compared to control cultures. When cultured on Matrigel (but not Monolayer) for 7 days, HDPSC formed tube-like structures in the VEGF treated group. This indicates the potential of use HDPSCs and their STRO-1 positive population for angiogenesis to enhance skeletal tissue repair and/or regeneration toward translational research for clinical benefit

Subchondral bone deterioration and osteophyte formation attributable to excessive mineralization are prominent features in the progression of end-stage knee osteoarthritis (OA). The cellular events underlying subchondral bone integrity diminishment remained elusive. This study was undertaken to characterize behavior and intracellular signaling of subchondral mesenchymal stem cells (SMSCs) and bone-marrow MSCs (BMMSCs) in OA knees isolated from patients with end-stage knee OA underwent total knee arthroplasty. The SMSCs isolated from subchondral bone explants expressed remarkable surface antigens CD73, CD105, CD90, CD166, CD44, CD29, instead of MHC II, CD45, and CD31. The cell cultures exhibited high proliferation capacity concomitant with low population doubling time compared to those of BMMSCs. Incubation in differentiation media, the SMSCs showed high osteogenic and chondrogenic lineage commitment and low adipogenic differentiation potential. They also exhibited high expression of embryonic stem cell marker OCT3/4, osteogenic factors Wnt3a, β-catenin and microRNA-29a (miR-29a) in conjunction with low expression of joint-deleterious factors HDAC4, TGF-β1, IL-1β, TNFα, and MMP3. Loss of miR-29a function lowered HDAC4 level, mineralized matrix accumulation and osteogenic marker expression of SMSCs. miR-29a reduced HDAC4 translation through targeting the 3”-untranslated region of HDAC4, which concomitantly sustained Wnt3a and β-catenin signaling. Collectively, high osteogenic lineage commitment existed in the SMSCs in OA knee microenvironment. miR-29a modulation of HDAC4 and Wnt3a signaling contributed to the increases in osteogenesis. This study shines a light no the biological role of MSCs in subchondral compartment in the end-stage OA development and highlights a new source of MSCs for joint tissue repair

Autologous bone grafting is a standard procedure for the clinical repair of skeletal defects, and good results have been obtained. Autologous vascularized bone grafting is currently the procedure of choice because of high osteogenic potential and resistance against reabsorption. Disadvantages of this procedure include limited availability of donor sites, clinical difficulty in handling, and a failure rate exceeding 10%. Allografts are often used for massive bone loss, but since only the marginal portion is newly vascularized after the implantation non healing fractures are often reported, along with a graft reabsorption. To overcome these problems, some studies in literature tried to conjugate bone graft and vascular supply, with encouraging results. On the other side, several studies in literature reported the ability of bone marrow derived cells to promote neo-vascularization. In fact, bone marrow contains not only hematopoietic stem cells (HSCs) and MSCs as a source for regenerating tissues but also accessory cells that support angiogenesis and vasculogenesis by producing several growth factors. In this scenario a new procedure was developed, consisting in an allogenic bone graft transplantation in a critical size defect in rabbit radius, plus a deviation at its inside of the median artery and vein with a supplement of autologous bone marrow concentrate on a collagen scaffold. Twenty-four New Zealand male white rabbits (2500–3000 g) were divided into 2 groups, each consisting of 12 animals. Surgeries were performed as follow:. −. Group 1 (#12): allogenic bone graft (left radius) / allogenic bone graft + vascular pedicle + autologous bone marrow concentrate (right radius). −. Group 2 (#12): sham operated (left radius)/ allogenic bone graft + vascular pedicle (right radius). For each group, 3 experimental time: 8, 4 and 2 weeks (4 animals for each time). The bone used as graft was previously collected from an uncorrelated study. An in vitro evaluation of bone marrow concentrate was performed in all cases, and at the time of sacrifice histological and histomorphometrical assessment were performed with immunohistochemical assays for VEGF, CD31 e CD146 to highlight the presence of vessels and endothelial cells. Micro-CT Analysis with quantitative bone evaluation was performed in all cases. The bone marrow concentrate showed a marked capability to differentiate into osteogenic, chondrogenic and agipogenic lineages. No complications such as infection or intolerance to the procedure were reported. The bone grafts showed only a partial integration, mainly at the extremities in the group with vascular and bone marrow concentrate supplement, with a good and healthy residual bone. immunohistochemistry showed an interesting higher VEGF expression in the same group. Micro CT analysis showed a higher remodeling activities in the groups treated with vascular supplement, with an area of integration at the extremities increasing with the extension of the sacrifice time. The present study suggests that the vascular and marrow cells supplement may positively influence the neoangiogenesis and the neovascularization of the homologous bone graft. A longer time of follow up and improvement of the surgical technique are required to validate the procedure

Mesenchymal stem cells (MSCs) are self-renewing, multipotent cells that could potentially be used to repair injured cartilage in diseases. The objetive was to analyze different sources of human MSCs to find a suitable alternative source for the isolation of MSCs with high chondrogenic potential. Femoral bone marrow, adipose tissue from articular and subcutaneous locations (hip, knee, hand, ankle and elbow) were obtained from 35 patients who undewent different types of orthopedic surgery (21 women, mean age 69.83 ± 13.93 (range 38–91) years. Neoplasic and immunocompromised patients were refused. The Ethical Committee for Clinical Research of the Government of Aragón (CEICA) approved the study and all patients provided informed consent. Cells were conjugated wiith monoclonal antibodies. Cell fluorescence was evaluated by flow cytometry using a FACSCalibur flow cytometer and analysed using CellQuest software (Becton Dickinson). Chondrogenic differentiation of human MSCs from the various tissues at P1 and P3 was induced in a 30-day micropellet culture [Pittenger et al., 1999]. To evaluate the differentiation of cartilaginous pellet cultures, samples were fixed embedded in paraffin and cut into 5- υm-thick slices. The slices were treated with hematoxylin-eosin and safranin O (Sigma-Aldrich). Each sample was graded according to the Bern Histological Grading Scale [Grogan et al., 2006], which is a visual scale that incorporates three parameters indicative of cartilage quality: uniform and dark staining with safranin O, cell density or extent of matrix produced and cellular morphology (overall score 0–9). Stained sections were evaluated and graded by two different researchers under a BX41 dual viewer microscope or a Nikon TE2000-E inverted microscope with the NIS-Elements software. Statistics were calculated using bivariate analysis. Pearson's χ2 or Fisher's exact tests were used to compare the Bern Scores of various tissues. To evaluate the cell proliferation, surface marker expression and tissue type results, ANOVA or Kruskal-Wallis tests were used, depending on the data distribution. Results were considered to be significant when p was < 0.05. MSCs from all tissues analysed had a fibroblastic morphology, but their rates of proliferation varied. Subcutaneous fat derived MSCs proliferated faster than bone marrow. MSCs from Hoffa fat, hip and knee subcutaneous proliferated slower than MSCs from elbow, ankle and hand subcutaneous. Flow cytometry: most of cells lacked expression of CD31, CD34, CD36, CD117 (c-kit), CD133/1 and HLA-DR. At same time 95% of cells expressed CD13, CD44, CD59, CD73, CD90, CD105, CD151 y CD166. Fenotype showed no differences in cells from different anatomic places. Cells from hip and knee subcutaneous showed a worst differentiation to hyaline cartilage. Hoffa fat cells showed high capacity in transforming to hyaline cartilage. Cells from different anatomic places show different chondrogenic potential that has to be considered to choose the cells source

Introduction. Discogenic pain is associated with ingrowth of blood vessels and nerves, but uncertainty over the extent of ingrowth is hindering development of appropriate treatments. We hypothesise that adult human annulus fibrosus is such a dense crosslinked tissue that ingrowth via the annulus is confined to a) peripheral regions, and b) fissures extending into the annulus. Methods. Disc tissue was examined from 61 patients (aged 37–75 yrs) undergoing surgery for disc herniation, degeneration or scoliosis. 5 µm sections were stained with H&E to identify structures and tissue types. 30 µm frozen sections were examined using confocal microscopy, following immunostaining for CD31 (an endothelial cell marker), PGP 9.5 and Substance P (general and nociceptive nerve markers, respectively). Fluorescent tags were attached to the antibodies. ‘Volocity’ software was used to calculate numbers and total cross-sectional area of labelled structures, and to measure their distance from the nearest free surface (disc periphery, or annulus fissure). Results. Maximum penetration of blood vessels and nerves from the peripheral annulus was 4,800 µm and 2,200 µm respectively. Maximum distance of nerves and vessels from the nearest free surface was 236 µm and 888 µm. Substance P (but not PGP 9.5) was co-localised with blood vessels, and both number and area of Substance P-stained structures were inversely correlated with grade of disc degeneration. Interpretation. Thick sections and fluorescent markers can show reliably where labelled structures are not present. Results therefore support our hypothesis: deep penetration of nerves into the human annulus occurs only if fissures are present. No conflicts of interest. No funding obtained. This abstract has not been previously published in whole or in part; nor has it been presented previously at a national meeting

Introduction. Severe ‘discogenic’ back pain may be related to the ingrowth of nerves and blood vessels, although this is controversial. We hypothesise that ingrowth is greater in painful discs, and is facilitated in the region of annulus fissures. Methods. We compared tissue removed at surgery from 22 patients with discogenic back pain and/or sciatica, and from 16 young patients with scoliosis who served as controls. Wax-embedded specimens were sectioned at 7μm. Nerves and blood vessels were identified using histological stains, and antibodies to PGP 9.5 and CD31 respectively. Results. Blood vessels were identified in 77% of ‘painful’ discs compared to 44% of scoliotic discs (p=0.013), and they were more common in the anterior anulus compared to the posterior (p=0.026). Maximum penetration of blood vessels from the peripheral anulus was 4.7 mm (in ‘painful’ discs) and 2.0 mm (in control discs), and penetration increased with histological grade of disc degeneration in the ‘painful’ discs (p=0.002). In 16/17 ‘painful’ discs, blood vessels were within 1 mm of an anulus fissure, or the disc periphery. Nerves were found in 36% of ‘painful’ discs (all with blood vessels) and 25% of control discs. Nerve ingrowth was always less than or equal to blood vessel ingrowth, with a maximum observed penetration of 1.5 mm from the annulus periphery. Discussion. In degenerated and painful discs, the ingrowth of nerves appears to follow that of blood vessels, and is facilitated in the region of annulus fissures. No nerves were seen >2mm from the annulus periphery, suggesting that previous reports of nerves in the disc nucleus may refer to vertical growth from a vertebral endplate rather than radial growth through the annulus. Results support the view that discogenic back pain is associated with pain-sensitisation events in the disc periphery. Acknowledgements. Research funded by BackCare. M Stefanakis would like to thank the Greek Institute of Scholarships (I.K.Y) for financial support

Summary. The donor-matched comparison between mesenchymal stem cells from knee infrapatellar and subcutaneous adipose tissue revealed their preferential commitment towards the chondrogenic and osteogenic lineage, respectively. These peculiarities could be relevant for the development of successful bone and cartilage cell-based applications. Introduction. Mesenchymal stem cells (MSCs) have been proposed in bone and cartilage tissue engineering applications as an alternative to terminally differentiated cells. In the present study we characterised and performed a donor-matched comparison between MSCs resident within the infrapatellar fat pad (IFP-MSCs) and the knee subcutaneous adipose tissue (ASCs) of osteoarthritic patients. These two fat depots, indeed, can be considered appealing candidates for orthopaedic cell-based therapies since they are highly accessible during knee surgery. Materials and Methods. IFP-MSCs and ASCs were obtained from 25 osteoarthritic patients undergoing total knee replacement. Undifferentiated cells were compared for their clonogenic ability and surface markers expression. Adipogenic, osteogenic and chondrogenic differentiative potentials were evaluated after IFP-MSCs and ASCs induction towards the various lineages by means of histological, biochemical and gene expression analysis of characteristic markers. Results. We found that undifferentiated IFP-MSCs and ASCs displayed a high clonogenic ability and the typical immunophenotype of MSCs (CD13. +. /CD29. +. /CD44. +. /CD73. +. /CD90. +. /CD105. +. /CD166. +. /CD31. −. /CD45. −. ), without any difference in terms of surface markers expression between these two cell populations. When both cell types were cultured in adequate adipo-, osteo- and chondro- differentiative media, IFP-MSCs and ASCs showed similar adipogenic potential, though undifferentiated ASCs had superior LEP expression compared to undifferentiated IFP-MSCs (p<0.01). ASCs showed a higher response to osteogenic induction in comparison with IFP-MSCs as demonstrated by significantly higher levels of calcified matrix deposition (p<0.05) and alkaline phosphatase activity (p<0.05). After 14 days of chondrogenic induction of cells cultured in pellets, we observed greater amounts of glycosaminoglycans (p<0.01) in IFP-MSCs pellets compared to ASCs pellets. Chondrogenic differentiation of IFP-MSCs showed also a superior gene expression of ACAN (p<0.001), SOX9, COMP (p<0.001) and COL2A1 (p<0.05) compared to ASCs. Furthermore, IFP-MSCs showed significantly lower levels of COL10A1 (p<0.05) and COL1A1 (p<0.01) and lower alkaline phosphatase release (p<0.05) compared to ASCs, supporting the hypothesis of a superior chondrogenic commitment of IFP-MSCs. Discussion/Conclusion. The observed dissimilarities between IFP-MSCs and ASCs suggest that despite similar features at the undifferentiated state, MSCs deriving from different anatomical sites within the same joint can display a specific commitment. The peculiar commitment of IFP-MSCs and ASCs towards the chondrogenic and osteogenic lineage suggests that they may be preferentially used for cartilage and bone applications, respectively