Autologous chondrocyte implantation provides good long-term clinical results in the treatment of knee osteoarthritis: a systematic review.

PURPOSE: To evaluate the mid- and long-term efficacy of autologous chondrocyte implantation (ACI) and matrix-assisted chondrocyte implantation (MACI) to treat patients with knee cartilage defects in the presence of osteoarthritis (OA). METHODS: PubMed and Cochrane databases were systematically searched for studies describing the treatment of knee OA with ACI or MACI (Kellgren-Lawrence (KL) ≥ 1, minimum follow-up 36 months). Results were reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines and included Lysholm, Western Ontario McMaster University and International Knee Documentation Committee scores. RESULTS: Of the 127 full-text articles assessed for eligibility, only five studies were selected based on inclusion/exclusion criteria (2 on ACI and 3 on MACI). In both groups, the defects were mainly located at femoral level, size 2.2-15.1 cm2 in the ACI and 2.0-7.6 cm2 in the MACI group. ACI was mostly used for patients affected by KL I, whereas MACI for patients with KL II-IV. The data obtained from 235 patients (161 ACI, 74 MACI) showed that ACI and MACI sustained stable clinical improvements up to 11 and 15 years, respectively, with a failure rate of about 10% up to 11 years. Scarce biological details regarding chondrocyte implantation were reported. CONCLUSIONS: ACI and MACI procedures for the treatment of knee cartilage lesions associated to OA showed long-term success and allowed delaying arthroplasty. Additional trials reporting homogenous data and precise patient characterization are needed to conduct an effective literature meta-analysis and identify the clinical relevance of these procedures. LEVEL OF EVIDENCE: IV.

A survey on surgeon practice shows lack of consensus on the management of primary shoulder stiffness.

Shoulder stiffness is a condition of painful restriction in active and passive glenohumeral range of motion, which can arise spontaneously or as consequence of a known cause. Numerous therapeutic approaches are available; however, no consensus has been reached on the best algorithm for successful treatment. The aim of this study was to investigate local practice patterns regarding management of primary shoulder stiffness. Randomized controlled trials reporting results of shoulder stiffness treatment were collected and analyzed prior to study begin. Controversial elements in the treatment of primary shoulder stiffness were identified and a survey was created and administrated to clinicians participating at an annual national congress dedicated to shoulder pathologies and their treatment. 55 completed questionnaires were collected. Physical therapy was recommended by 98% of the interviewed. The use of oral corticosteroids was considered by 58% and injections of corticosteroids by 60%. Injective therapy with local anaesthetics was considered by 56% of the clinicians and acupuncture by 36%. 38% of the interviewed did never treat shoulder stiffness surgically. Various strategies to manage shoulder stiffness have been proposed and high-level evidence has been published. Numerous controversial points and a substantial lack of consensus emerged both from literature reviews and from this survey. The treatment of shoulder stiffness should be tailored to the patient's clinical situation and the stage of its pathology, aiming primarily at identifying risk factors for recurrence, reducing pain, restoring range of motion and function and shortening the duration of symptoms.

Hamstring grafts are tenogenic constructs for ACL reconstruction and Pulsed Electromagnetic Fields improve tendon specific markers expression. An in-vitro study.

Hamstring tendons represent one of the commonest autologous graft used during ACL reconstruction. The harvest of the tendon and the time of tendon processing on the operating table, together with the pretensioning maneuvers and the permanence out of the joint during the time of surgery, might impair tendon derived cells (TCs) viability. The aim of the study was: i) to assess the effective viability of the TCs at the end of the surgical procedure; ii) to investigate if TCs viability and the expression of tendon specific markers may be improved through exposure to prolonged pulsed electromagnetic fields (PEMF) similar to that of clinical practice. Remnants of semitendinosus and gracilis tendons (discarded at the end of the ACL reconstruction) were collected from 13 healthy donors. To isolate TCs, the tendon tissue was minced and digested enzymatically with 0.3% type I collagenase in DMEM with continuous agitation for 15 h at 37°C. The isolated nucleated cells were then plated at 5x103 cells/cm2 in a complete medium composed of DMEM, 10% fetal bovine serum, 50 U/ml Penicillin, 50 mg/ml Streptomycin, 2 mM L-glutamine, and supplemented with 5 ng/ml basic fibroblast growth factor (b-FGF). They were maintained at 37 °C in a humidified atmosphere with 5% CO2, changing culture medium every 3 days. When they reached 80-90% of confluence, the cells were detached by incubation with trypsin/EDTA and then cultured at a density of 5x103 cells/cm2. TCs were cultured in complete medium for 7, 14, 21 days (in chamber slides, to optimize the final immunofluorescence analysis). The following cell cultures were set up: i) TCs cultured with differentiation medium + exposure to PEMF 8 h/day; ii) TCs cultured with differentiation medium without exposure to PEMF. The stimulation with PEMF was generated by a pair of electrical coils, connected with the generator of pulsed electromagnetic fields (PEMF generator system IGEA, Carpi, Italy, intensity of magnetic field = 1.5 mT, frequency = 75 Hz). At day 0, day 7, day 14 and day 21 immunofluorescence analysis was performed to evaluate the expression of tendon specific markers (collagen type I, collagen type VI, scleraxis) and proliferative markers (PCNA, beta-catenin). The TCs from the hamstring tendon fragments at the end of the ACL reconstruction were alive and they expressed markers of proliferation and tendon phenotype at the end of the culture period. The TCs in the presence of PEMF 8h/day showed a greater production of collagen type I, collagen type VI and scleraxis than TCs cultured without PEMF (p<0.05). The expression of these markers increased from 7 to 21 days of culture. The expression of proliferative markers in the presence of PEMF stimulus was significantly lower (p<0.05) than that of TCs cultured without PEMF. Hamstring tendons are not simple "tenoconductive" scaffolds but biologic alive tenogenic constructs rich in cells that can sustain tenogenic behavior and tendon matrix synthesis. Prolonged exposure to PEMF improves their phenotype. Thus, from a clinical perspective, the use of PEMF may represent a possible future strategy to positively influence the early phase of graft remodeling and, ultimately, improve the ligamentization process. Following these concepts, further studies might also exploit the anabolic role of PEMF as an adjunctive postoperative strategy in different tendon pathologies.

Tips and tricks for writing a scientific manuscript.

An original scientific manuscript is the target for any researchers whose aim is to show the innovative results arising from the original intuitions that drove all their experiments. Time and patience are essential to decide how to present the data, how to conceive the tables and figures representing the main outcomes of the research, and how to read and mention the necessary references. Few basic rules may help in this difficult task. The first basic rule is: "do not follow the sequence of the paper". On the opposite, i) start writing the "Materials and Methods (or Patients and Methods when dealing with a clinical study)", ii) then write the "Results" section, iii) then, write the "Discussion" paragraph, in which the principal investigator explains the results and the innovations proposed, iv) then, write the "Introduction", which should be clear and concise. The last element to be written should be the "Abstract", which is the "interface" between the authors and the readers. The second basic rule is that any of the central chapters of the manuscript, i.e. "Materials and Methods" (MM), "Results" (R) and "Discussion" (D), should follow a methodical and sequential description of the topics in a "corresponding sequence of paragraphs". In other words, in the R and the D chapter sequence of the paragraphs should be linked to the sequence of the concepts described and discussed in the paragraphs of the MM chapter. Thus, a sequential description of concepts will be easily followed by the writers, facilitating both the authors in the organization of the data and the reader in finding a reasonable "answer" to all the aspects of the study mentioned in the MM chapter. In this article, these two rules are extensively described and several tips and tricks for each chapter are suggested to ease the composition of a scientific paper. Indeed, it may be possible to solve the complex problem of "writing a scientific paper" by means of separating it in main sections (chapters) and subsections (paragraphs) and dealing with them one by one. Naturally, this takes time and passion, but, as affirmed by Steve Jobs, "the only way to do great work is to love what you do".

Intervertebral disc and endplate cells response to IL-1ß inflammatory cell priming and identification of molecular targets of tissue degeneration.

Inflammation represents an important factor leading to metabolic imbalance within the intervertebral disc (IVD), conducive to degenerative changes. Therefore, a thorough knowledge of the IVD and endplate (EP) cell behaviour in such pathological environments is essential when designing regenerative therapeutic strategies. The present study aimed at assessing the molecular response of the IVD constitutive nucleus pulposus (NPCs)-, annulus fibrosus (AFCs)- and endplate (EPCs)-derived cells to interleukin (IL)-1ß treatment, through large-scale, high-throughput microarray and protein analysis, identifying the differentially expressed genes and released proteins. Overall, the inflammatory stimulus downregulated stemness genes while upregulating pro-inflammatory, pro-angiogenic and catabolic genes, including matrix metalloproteases, which were not balanced by a concomitant upregulation of their inhibitors. Upregulation of anti-inflammatory and anabolic tumour necrosis factor inducible gene 6 protein (TNFAIP6), of IL-1 receptor antagonist (IL-1Ra) (at gene and protein levels) and of trophic insulin-like growth factor 1 (IGF1) was also observed in all cell types; IGF1 particularly in AFCs. An overall inhibitory effect of tumour necrosis factor alpha (TNFα) signal was observed in all cell types; however, EPCs showed the strongest anti-inflammatory behaviour. AFCs and EPCs shared the ability to limit the activation of the signalling mediated by specific chemokines. AFCs showed a slightly senescent attitude, with a downregulation of genes related to DNA repair or pro-mitosis. Results allowed for the identification of specific molecular targets in IVD and EP cells that respond to an inflammatory environment. Such targets can be either silenced (when pathological targets) or stimulated to counteract the inflammation.

Intervertebral disc and endplate cell characterisation highlights annulus fibrosus cells as the most promising for tissue-specific disc degeneration therapy.

Degenerative processes of the intervertebral disc (IVD) and cartilaginous endplate lead to chronic spine pathologies. Several studies speculated on the intrinsic regenerative capacity of degenerated IVD related to the presence of local mesenchymal progenitors. However, a complete characterisation of the resident IVD cell populations, particularly that isolated from the endplate, is lacking. The purpose of the present study was to characterise the gene expression profiles of human nucleus pulposus (NPCs), annulus fibrosus (AFCs) and endplate (EPCs) cells, setting the basis for future studies aimed at identifying the most promising cells for regenerative purposes. Cells isolated from NP, AF and EP were analysed after in vitro expansion for their stemness ability, immunophenotype and gene profiles by large-scale microarray analysis. The three cell populations shared a similar clonogenic, adipogenic and osteogenic potential, as well as an immunophenotype with a pattern resembling that of mesenchymal stem cells. NPCs maintained the greatest chondrogenic potential and shared with EPCs the loss of proliferation capability during expansion. The largest number of selectively highly expressed stemness, chondrogenic/tissue-specific and surface genes was found in AFCs, thus representing the most promising source of tissue-specific expanded cells for the treatment of IVD degeneration.

Current trends in tendinopathy: consensus of the ESSKA basic science committee. Part II: treatment options.

The treatment of painful chronic tendinopathy is challenging. Multiple non-invasive and tendon-invasive methods are used. When traditional non-invasive treatments fail, the injections of platelet-rich plasma autologous blood or cortisone have become increasingly favored. However, there is little scientific evidence from human studies supporting injection treatment. As the last resort, intra- or peritendinous open or endoscopic surgery are employed even though these also show varying results. This ESSKA basic science committee current concepts review follows the first part on the biology, biomechanics and anatomy of tendinopathies, to provide a comprehensive overview of the latest treatment options for tendinopathy as reported in the literature.

Evaluation of the use of autologous micro-fragmented adipose tissue in the treatment of knee osteoarthritis: preliminary results of a randomized controlled trial.

Articular cartilage injuries are still unsolved due to the limited intrinsic healing potential of this tissue. Unlike other tissues, inflammation in the synovial joint causes perpetual damage and progressively leads to the development of osteoarthritis. Previous in vitro and in vivo studies have demonstrated the efficacy of mesenchymal stem cells isolated from adipose tissue in modulating inflammation. In this study, we analyzed the role of these cells in modifying the pathological microenvironment present in knee osteoarthritis. This is an interventional, prospective, randomized, controlled study. Starting from June 2017, 39 patients with grade III and IV knee osteoarthritis of Kellgren-Lawrence were enrolled, aged between 45 and 75 years, with pain greater than or equal to 6 according to the VAS scale, without ligament instability, with an axial deviation not greater than 10° and with a BMI between 18 and 30. The control group underwent an arthroscopic debridement, while the experimental group underwent an arthroscopic debridement and a subsequent intra-articular injection of autologous micro-fragmented adipose tissue. Patients were evaluated before surgery and at 6 months after the procedure, by radiological analysis (MRI) and functional outcome measures. The main purpose of the study is to evaluate the symptomatic improvement by comparing the functional outcome scores between the two groups. At 6 months after treatment, preliminary results on 39 patients showed pain reduction and functional improvements in the experimental group without a significant difference due to the low number of patients. The radiological and biochemical analyses are still ongoing. To date, the study has not revealed any side effects. These preliminary results demonstrate an encouraging positive trend in the experimental group. Patient recruitment is still ongoing to finalize the statistical analyses and to confirm our hypothesis.

Current trends in tendinopathy: consensus of the ESSKA basic science committee. Part I: biology, biomechanics, anatomy and an exercise-based approach.

Chronic tendinopathies represent a major problem in the clinical practice of sports orthopaedic surgeons, sports doctors and other health professionals involved in the treatment of athletes and patients that perform repetitive actions. The lack of consensus relative to the diagnostic tools and treatment modalities represents a management dilemma for these professionals. With this review, the purpose of the ESSKA Basic Science Committee is to establish guidelines for understanding, diagnosing and treating this complex pathology.

Different culture conditions affect the growth of human tendon stem/progenitor cells (TSPCs) within a mixed tendon cells (TCs) population.

BACKGROUND: Tendon resident cells (TCs) are a mixed population made of terminally differentiated tenocytes and tendon stem/progenitor cells (TSPCs). Since the enrichment of progenitors proportion could enhance the effectiveness of treatments based on these cell populations, the interest on the effect of culture conditions on the TSPCs is growing. In this study the clonal selection and the culture in presence or absence of basic fibroblast growth factor (bFGF) were used to assess their influences on the stemness properties and phenotype specific features of tendon cells. METHODS: Cells cultured with the different methods were analyzed in terms of clonogenic and differentiation abilities, stem and tendon specific genes expression and immunophenotype at passage 2 and passage 4. RESULTS: The clonal selection allowed to isolate cells with a higher multi-differentiation potential, but at the same time a lower proliferation rate in comparison to the whole population. Moreover, the clones express a higher amounts of stemness marker OCT4 and tendon specific transcription factor Scleraxis (SCX) mRNA, but a lower level of decorin (DCN). On the other hand, the number of cells obtained by clonal selection was extremely low and most of the clones were unable to reach a high number of passages in cultures. The presence of bFGF influences TCs morphology, enhance their proliferation rate and reduce their clonogenic ability. Interestingly, the expression of CD54, a known mesenchymal stem cell marker, is reduced in presence of bFGF at early passages. Nevertheless, bFGF does not affect the chondrogenic and osteogenic potential of TCs and the expression of tendon specific markers, while it was able to downregulate the OCT4 expression. CONCLUSION: This study showed that clonal selection enhance progenitors content in TCs populations, but the extremely low number of cells produced with this method could represent an insurmountable obstacle to its application in clinical approaches. We observed that the addition of bFGF to the culture medium promotes the maintenance of a higher number of differentiated cells, reducing the proportion of progenitors within the whole population. Overall our findings demonstrated the importance of the use of specific culture protocols to obtain tendon cells for possible clinical applications.

Regenerative approaches for the treatment of early OA.

The diagnosis and the prompt treatment of early osteoarthritis (OA) represent vital steps for delaying the onset and progression of fully blown OA, which is the most common form of arthritis, involving more than 10 % of the world's population older than 60 years of age. Nonsurgical treatments such as physiotherapy, anti-inflammatory medications, and other disease-modifying drugs all have modest and short-lasting effect. In this context, the biological approaches have recently gained more and more attention. Growth factors, blood derivatives, such as platelet concentrates, and mesenchymal adult stem cells, either expanded or freshly isolated, are advocated amongst the most promising tool for the treatment of OA, especially in the early phases. Primarily targeted towards focal cartilage defects, these biological agents have indeed recently showed promising results to relieve pain and reduce inflammation in patients with more advanced OA as well, with the final aim to halt the progression of the disease and the need for joint replacement. However, despite of a number of satisfactory in vitro and pre-clinical studies, the evidences are still limited to support their clinical efficacy in OA setting.

Open Latarjet versus arthroscopic Latarjet: clinical results and cost analysis.

PURPOSE: The aim of this study was to compare the clinical results between open and arthroscopic Latarjet and perform a cost analysis of the two techniques. MATERIALS AND METHODS: A systematic review of articles present in PubMed and MEDLINE was performed in accordance with PRISMA guidelines. Studies concerning post-operative outcomes following Latarjet procedures for chronic anterior shoulder instability were selected for analysis. The clinical and radiographic results as well as the costs of the open and arthroscopic techniques were evaluated. RESULTS: Twenty-three articles, describing a total of 1317 shoulders, met the inclusion criteria: 17 studies were related to open Latarjet, and 6 to the arthroscopic technique. Despite the heterogeneity of the evaluation scales, the clinical results seemed very satisfactory for both techniques. We detected a statistically significant difference in the percentage of bone graft healing in favour of the open technique (88.6 vs 77.6 %). Recurrent dislocation was more frequent following open surgery (3.3 % after open surgery vs 0.3 % after arthroscopy), but this finding was biased by the large difference in follow-up duration between the two techniques. The direct costs of the arthroscopic procedure were double in comparison to open surgery (€2335 vs €1040). A lack of data prevented evaluation of indirect costs and, therefore, a cost-effectiveness analysis. CONCLUSIONS: The open and arthroscopic Latarjet techniques showed excellent and comparable clinical results. However, the much higher direct costs of the arthroscopic procedure do not seem, at present, to be justified by a benefit to the patient. LEVEL OF EVIDENCE: III.

Sustained five-year benefit of autologous matrix-induced chondrogenesis for femoral acetabular impingement-induced chondral lesions compared with microfracture treatment.

The repair of chondral lesions associated with femoroacetabular impingement requires specific treatment in addition to that of the impingement. In this single-centre retrospective analysis of a consecutive series of patients we compared treatment with microfracture (MFx) with a technique of enhanced microfracture autologous matrix-induced chondrogenesis (AMIC). Acetabular grade III and IV chondral lesions measuring between 2 cm(2) and 8 cm(2) in 147 patients were treated by MFx in 77 and AMIC in 70. The outcome was assessed using the modified Harris hip score at six months and one, two, three, four and five years post-operatively. The outcome in both groups was significantly improved at six months and one year post-operatively. During the subsequent four years the outcome in the MFx group slowly deteriorated, whereas that in the AMIC group remained stable. Six patients in the MFx group subsequently required total hip arthroplasty, compared with none in the AMIC group We conclude that the short-term clinical outcome improves in patients with acetabular chondral damage following both MFx and AMIC. However, the AMIC group had better and more durable improvement, particularly in patients with large (≥ 4 cm(2)) lesions.

Why menisci show higher healing rate when repaired during ACL reconstruction? Growth factors release can be the explanation.

PURPOSE: Healing rate of meniscus repair is higher when the suture is associated with anterior cruciate ligament reconstruction. A possible explanation can be a different pattern of release of growth factors between anterior cruciate ligament reconstruction and isolated meniscus surgery. Hypothesis of this study is that the concentrations of bFGF, TGF-ß and platelet-derived growth factor (PDGF) in joint fluid, immediately after single-bundle anterior cruciate ligament reconstruction and arthroscopic partial meniscectomy, can be different. METHODS: Twenty consecutive patients underwent partial medial meniscectomy and twenty consecutive patients underwent single-bundle anterior cruciate ligament reconstruction with hamstring grafts were enrolled in the study. Thirty minutes after the end of the surgical procedure, a sample of joint fluid, as well of venous blood, was collected from all the patients. Concentrations of growth factors were determined by enzyme-linked immunosorbent assay. RESULTS: The peripheral blood concentration of TGF-ß, bFGF and PDGF was comparable between partial meniscectomy and anterior cruciate ligament reconstruction groups. No differences between the two surgical techniques were also found in term of TGF-ß and bFGF joint fluid concentration, whereas joint PDGF concentration of anterior cruciate ligament reconstruction patients was significantly higher than the one found in partial meniscectomy patients. CONCLUSIONS: A significant growth factors release was detected in the knee joint during arthroscopic surgery. PDGF concentration was significantly higher in anterior cruciate ligament reconstructed knee than in the meniscectomy group. PDGF can play an important role enhancing the healing response of meniscus suture and can be one of the biological reasons of the higher meniscal healing rate in anterior cruciate ligament reconstructed knee.

In vitro functional response of human tendon cells to different dosages of low-frequency pulsed electromagnetic field.

PURPOSE: Chronic tendinopathy is a degenerative process causing pain and disability. Current treatments include biophysical therapies, such as pulsed electromagnetic fields (PEMF). The aim of this study was to compare, for the first time, the functional in vitro response of human tendon cells to different dosages of PEMF, varying in field intensity and duration and number of exposures. METHODS: Tendon cells, isolated from human semitendinosus and gracilis tendons (hTCs; n = 6), were exposed to different PEMF treatments (1.5 or 3 mT for 8 or 12 h, single or repeated treatments). Scleraxis (SCX), COL1A1, COL3A1 and vascular endothelial growth factor-A (VEGF-A) expression and cytokine production were assessed. RESULTS: None of the different dosages provoked apoptotic events. Proliferation of hTCs was enhanced by all treatments, whereas only 3 mT-PEMF treatment increased cell viability. However, the single 1.5 mT-PEMF treatment elicited the highest up-regulation of SCX, VEGF-A and COL1A1 expression, and it significantly reduced COL3A1 expression with respect to untreated cells. The treated hTCs showed a significantly higher release of IL-1ß, IL-6, IL-10 and TGF-ß. Interestingly, the repeated 1.5 mT-PEMF significantly further increased IL-10 production. CONCLUSIONS: 1.5 mT-PEMF treatment was able to give the best results in in vitro healthy human tendon cell culture. Although the clinical relevance is not direct, this investigation should be considered an attempt to clarify the effect of different PEMF protocols on tendon cells, in particular focusing on the potential applicability of this cell source for regenerative medicine purpose, both in surgical and in conservative treatment for tendon disorders.

Donor-matched mesenchymal stem cells from knee infrapatellar and subcutaneous adipose tissue of osteoarthritic donors display differential chondrogenic and osteogenic commitment.

Cell-based therapies have recently been proposed for the treatment of degenerative articular pathologies, such as early osteoarthritis, with an emphasis on autologous mesenchymal stem cells (MSCs), as an alternative to terminally differentiated cells. In this study, we performed a donor-matched comparison between infrapatellar fat pad MSCs (IFP-MSCs) and knee subcutaneous adipose tissue stem cells (ASCs), as appealing candidates for cell-based therapies that are easily accessible during surgery. IFP-MSCs and ASCs were obtained from 25 osteoarthritic patients undergoing total knee replacement and compared for their immunophenotype and differentiative potential. Undifferentiated IFP-MSCs and ASCs displayed the same immunophenotype, typical of MSCs (CD13+/CD29+/CD44+/CD73+/CD90+/CD105+/CD166+/CD31-/CD45-). IFP-MSCs and ASCs showed similar adipogenic potential, though undifferentiated ASCs had higher LEP expression compared to IFP-MSCs (p<0.01). Higher levels of calcified matrix (p<0.05) and alkaline phosphatase (p<0.05) in ASCs highlighted their superior osteogenic commitment compared to IFP-MSCs. Conversely, IFP-MSCs pellets showed greater amounts of glycosaminoglycans (p<0.01) and superior expression of ACAN (p<0.001), SOX9, COMP (p<0.001) and COL2A1 (p<0.05) compared to ASCs pellets, revealing a superior chondrogenic potential. This was also supported by lower COL10A1 (p<0.05) and COL1A1 (p<0.01) expression and lower alkaline phosphatase release (p<0.05) by IFP-MSCs compared to ASCs. The observed dissimilarities between IFP-MSCs and ASCs show that, despite expressing similar surface markers, MSCs deriving from different fat depots in the same surgical site possess specific features. Furthermore, the in vitro peculiar commitment of IFP-MSCs and ASCs from osteoarthritic donors towards the chondrogenic or osteogenic lineage may suggest a preferential use for cartilage and bone cell-based treatments, respectively.

Autologous collagen-induced chondrogenesis technique (ACIC) for the treatment of chondral lesions of the talus.

PURPOSE: Autologous collagen-induced chondrogenesis technique (ACIC) combines microfractures with the use of an injectable atelocollagen matrix that allows performing the whole cartilage repair treatment arthroscopically. The aim of this study was to evaluate the in vitro cytocompatibility of this biomaterial using human bone marrow mesenchymal stem cells and human chondrocytes. Moreover, the preliminary data of five patients affected by chondral lesion of the talus treated with the ACIC technique are shown. METHODS: Human bone marrow mesenchymal stem cells and human chondrocytes were seeded on solid and pre-solid atelocollagen scaffolds. Cell-scaffold constructs were cultured for 7 days and then prepared for histological analyses. Arthroscopic ACIC was performed in five patients affected by chondral lesions of the talus; they were clinically evaluated with AOFAS, VAS and Tegner score before and then after 6 months from surgery. RESULTS: In vitro results showed that both bone marrow mesenchymal stem cells and chondrocytes were able to efficiently colonize the whole construct, from the surface to the core, only when seeded on the pre-solid atelocollagen scaffold, but not on its solid form. No adverse events were observed in the patients treated with the ACIC technique; a significant improvement in VAS pain scale and in AOFAS score was found at 6 months follow up. CONCLUSION: Injectable atelocollagen can be considered a feasible scaffold for cartilage repair treatment, in particular if used in its pre-solid form. ACIC leads to good clinical results in the treatment for chondral lesions of the talus even if longer follow-up and a higher number of patients are necessary to confirm these data. LEVEL OF EVIDENCE: IV.

Stemness and osteogenic and adipogenic potential are differently impaired in subcutaneous and visceral adipose derived stem cells (ASCs) isolated from obese donors.

Today adipose tissue is not just considered as the primary energy storage organ, but it is also recognized as an important endocrine tissue and an abundant source of mesenchymal stem cells (adipose-derived stem cells, ASCs). During the last decade, several studies have provided preclinical data on the safety and efficacy of ASCs, supporting their use in cell-based therapy for regenerative medicine purposes. Little is known about the effect of obesity on ASCs properties. Since ASCs differentiation and proliferation are determined by their niche, the differences in body fat distribution and the obesity-related co-morbidities may have several consequences. In this study we compared ASCs of subcutaneous adipose tissue from obese (obS-ASCs) and non-obese (nS-ASCs) donors in order to compare their immunophenotype and osteogenic and adipogenic potential. Moreover, in order to evaluate the possible difference between subcutaneous and visceral fat, obS-ASCs were also compared to ASCs derived from visceral adipose tissue of the same obese donors (obV-ASCs). Our results show that subcutaneous and visceral ASCs derived from obese donors have an impaired cell proliferation, clonogenic ability and immunophenotype. Nevertheless, obS-ASCs are able to differentiate toward osteogenic and adipogenic lineages, although to a small extent with respect to non-obese donors, whereas obV-ASCs lose most of their stem cell characteristics, including multi-differentiation potential. Taken together our findings confirm that not all ASCs present the same behavior, most likely due to their biological microenvironment in vivo. The specific stimuli which can play a key role in ASCs impairment, including the effects of the obesity-related inflammation, should be further investigated to have a complete picture of the phenomenon.

Two bone substitutes analyzed in vitro by porcine and human adipose-derived stromal cells.

Nowadays, the repair of large bone defects is an important goal in orthopaedic and dental fields. Tissue engineering, applied to increase the bone regeneration process, combines suitable scaffolds with either terminally differentiated cells or Mesenchymal Stromal Cells. In vitro studies with Adipose-derived Stromal Cells (ASCs) may identify new bioactive supports, to be tested in preclinical model. In this study, we evaluated the biocompatibility and the osteoinductive properties of two bone substitutes, RegenOSS (RO-1) and a new generation scaffold (RO-2), on both porcine and human ASCs. Porcine ASCs need a prolonged initial phase to adapt to both substitutes; indeed, their growth was initially reduced respect to cells cultured in their absence. In contrast, human ASCs were not negatively affected. However, no toxicity of RO-1 and -2 was observed on both ASC populations which are able to stick to both biomaterials. RO-1 and -2 supported osteogenic differentiation of porcine and human ASCs in a different manner: the presence of RO-1 up-regulated both alkaline phosphatase (ALP) activity and collagen production of human ASCs, whereas in porcine ASCs, RO-2 seemed to up-regulate ALP activity, while the production of collagen is mainly stimulated by the presence of RO-1. We suggest to use not just human ASCs, but also animal ones to select suitable scaffolds to generate bio-constructs in vitro, which then need to be tested in animal model before reaching the market.