Interventional treatments for low back pain due to sacroiliac joint dysfunction: a systematic review of the literature.

PURPOSE: This systematic review aimed to report the current evidence in the literature about the efficacy of interventional treatments in the management of low back pain (LBP) due to sacroiliac joint dysfunction. METHODS: A systematic review was performed using the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. Medline, EMBASE, Scopus, CINAHL, Cochrane Library, and CENTRAL bibliographic databases were searched. The search was performed from October to December 2021, and articles from the inception of the database to December 2021 were searched. RESULTS: Fourteen studies were included for qualitative synthesis. Five studies used the traditional radiofrequency approach (tRF), five studies used cooled radiofrequency approach (cRF), one study used botulinum toxin (BT), two studies used steroid injection, triamcinolone (TA) and local anesthetics injections, and one study used pulsed radiofrequency (PRF) denervation. Two studies used sham as a comparator. CONCLUSIONS: Cooled radiofrequency seems to be the most effective treatment in improving pain and functionality, while intra-articular injections are helpful only as diagnostic tools. However, due to the lack of high-quality studies, it was not possible to draw significant conclusions.

Anterior Cruciate Ligament Repair Augmented With Dynamic Intraligamentary Stabilization Is Equivalent to Hamstring Autograft Reconstruction at Short- and Mid-Term Follow-Up: A Systematic Review.

PURPOSE: To compare clinical outcomes, knee stability and complications, failure, and revision rates after anterior cruciate ligament repair (ACLr) with dynamic intraligamentary stabilization (DIS) versus anterior cruciate ligament reconstruction (ACLR) with hamstring autograft for primary ACL ruptures at short and mid-term follow-up. METHODS: A Preferred Reporting Items for Systematic Reviews and Meta-Analyses-compliant systematic review of PubMed/MEDLINE and Scopus was performed. Studies that evaluated patients undergoing ACLr with DIS or ACLR with hamstring autograft were considered for inclusion. Studies were excluded if patients were affected by concomitant meniscal, ligamentous, or chondral injuries needing surgical treatment, because of their potential confounding effect on postoperative outcomes. The Risk of Bias-2 tool was used to assess the risk of bias in the included studies. The quality of available evidence was rated according to Grading of Recommendations Assessment, Development, and Evaluation recommendations. The study protocol was registered in the PROSPERO database (ID: CRD42023394558). RESULTS: Five randomized controlled trials comparing the outcomes of ACLr with DIS versus ACLR with hamstring autograft met the inclusion criteria. No major differences in terms of patient-reported outcomes (International Knee Documentation Committee subjective form, Lysholm score, Tegner activity scale, Knee injury and Osteoarthritis Outcome Score, visual analog scale satisfaction) or rates of complications, revisions, and failures were found in included studies at all time points. Repair showed greater International Knee Documentation Committee subjective form scores at 5 years in one study, whereas ACLR displayed significantly increased knee stability at 6 months and 5 years in 2 different studies, although the clinical relevance of these differences is doubtful. CONCLUSIONS: The results of this study suggest that ACLr with DIS is not inferior to ACLR with hamstring autograft in terms of rates of clinical outcomes, knee stability, risk of failure, complications, and revision surgery. Therefore, ACLr with DIS may be a viable alternative to ACLR with hamstring autograft in selected patients. LEVEL OF EVIDENCE: Level I, systematic review of Level I studies.

Improved cytocompatibility and antibacterial properties of zinc-substituted brushite bone cement based on ß-tricalcium phosphate.

For bone replacement materials, osteoconductive, osteoinductive, and osteogenic properties are desired. The bacterial resistance and the need for new antibacterial strategies stand among the most challenging tasks of the modern medicine. In this work, brushite cements based on powders of Zinc (Zn) (1.4 wt%) substituted tricalcium phosphate (ß-TCP) and non-substituted ß-TCP were prepared and investigated. Their initial and final phase composition, time of setting, morphology, pH evolution, and compressive strength are reported. After soaking for 60 days in physiological solution, the cements transformed into a mixture of brushite and hydroxyapatite. Antibacterial activity of the cements against Enterococcus faecium, Escherichia coli, and Pseudomonas aeruginosa bacteria strains was attested. The absence of cytotoxicity of cements was proved for murine fibroblast NCTC L929 cells. Moreover, the cell viability on the ß-TCP cement containing Zn2+ ions was 10% higher compared to the ß-TCP cement without zinc. The developed cements are perspective for applications in orthopedics and traumatology.

A Hyaluronan and Platelet-Rich Plasma Hydrogel for Mesenchymal Stem Cell Delivery in the Intervertebral Disc: An Organ Culture Study.

The purpose of the present pilot study was to evaluate the effect of a hydrogel composed of hyaluronic acid (HA) and platelet-rich plasma (PRP) as a carrier for human mesenchymal stem cells (hMSCs) for intervertebral disc (IVD) regeneration using a disc organ culture model. HA was mixed with batroxobin (BTX) and PRP to form a hydrogel encapsulating 1 × 106 or 2 × 106 hMSCs. Bovine IVDs were nucleotomized and filled with hMSCs suspended in ~200 µL of the PRP/HA/BTX hydrogel. IVDs collected at day 0 and nucleotomized IVDs with no hMSCs and/or hydrogel alone were used as controls. hMSCs encapsulated in the hydrogel were also cultured in well plates to evaluate the effect of the IVD environment on hMSCs. After 1 week, tissue structure, scaffold integration, hMSC viability and gene expression of matrix and nucleus pulposus (NP) cell markers were assessed. Histological analysis showed a better preservation of the viability of the IVD tissue adjacent to the gel in the presence of hMSCs (~70%) compared to the hydrogel without hMSCs. Furthermore, disc morphology was maintained, and the hydrogel showed signs of integration with the surrounding tissues. At the gene expression level, the hydrogel loaded with hMSCs preserved the normal metabolism of the tissue. The IVD environment promoted hMSC differentiation towards a NP cell phenotype by increasing cytokeratin-19 (KRT19) gene expression. This study demonstrated that the hydrogel composed of HA/PRP/BTX represents a valid carrier for hMSCs being able to maintain a good cell viability while stimulating cell activity and NP marker expression.

Prevalence of work related musculoskeletal disorders in Italian workers: is there an underestimation of the related occupational risk factors?

BACKGROUND: Work-related musculoskeletal disorders (WMSDs) represent an important socio-economic burden. The current risk assessment and management involved in the ethiopathogenesis of WMSDs is based on observational tools and checklists, which have some limitations in terms of accuracy and reliability. The aim of this study was to assess WMSD prevalence and identify possible correlations with several socio-demographic and work-related variables in a large cohort representative of Italian workers in order to improve our understanding of the WMSD phenomenon. METHODS: This study includes data from INSuLa, a cross-sectional nationally representative survey of health and safety at work, developed by the Italian Workers' Compensation Authority. A total of 8000 Italian workers were included. Multivariate logistic regression analyses were performed to evaluate the association of independent variables, such as workers' perceptions of exposure to biomechanical/ergonomic and video display unit (VDU) risks (Risk Perceived) and the actual risk exposure (Risk Detected) on Back, Lower and Upper limb pain. Socio-demographic, occupational and other health-related variables were included to investigate possible association with musculoskeletal disorders. RESULTS: Workers perceiving a significant exposure to biomechanical/ergonomic and VDU risks but not included in a health surveillance program for them (Risk Perceived/No Risk Detected) have had significantly higher odds of reporting musculoskeletal disorders. Regarding the biomechanical/ergonomic risk these workers are in the 19-24 age range (39.9%), transportation, warehousing/information and communication sectors (38.9%) and are employed in companies with more than 250 workers (35.8%). Regarding VDU risk, workers are in the 45-54 age range (24.5%), professional, financial and business services (38.0%) and come from companies with more than 250 employees (25.6%). CONCLUSIONS: Within the occupational safety and health management systems an appropriate assessment of occupational risk factors correlated to musculoskeletal disorders (mainly biomechanical/ergonomic and VDU) and the correct definition of their exposure levels is essential to adequately prevent the onset of WMSDs. In this regard, our findings provide useful information to design novel approaches, aimed at improving our understanding of emerging risks, identifying gaps in current risk assessment strategies and enhancing workplace interventions are mandatory to improve the occupational risk assessment and management process and therefore implement the subsequent health surveillance systems.

How to treat lumbar disc herniation in pregnancy? A systematic review on current standards.

PURPOSE: In this systematic review, we aim to illustrate the current and safe concepts in the assessment, diagnosis and management of herniated lumbar disc (HLD) during pregnancy. METHODS: A systematic review and reporting on the diagnosis, treatment and clinical results of HLD during pregnancy is performed. RESULTS: The MRI represents the first level and safest diagnostic tool for pregnant women affected by spinal problems allowing for a noninvasive and detailed radiological examination of the spine. The initial management of pregnant women affected by HLD is conservative, and primarily aimed to pain therapy. Whenever radicular pain and progressive neurological deficits unresponsive to medical management occur, surgery should be considered. Few case reports regarding the operative management of HLD in pregnant women have been published up to date. Laminectomy and/or microdiscectomy represent the classical and most commonly used techniques that can be safely performed without affecting pregnancy, delivery, or baby's health. Endoscopic discectomy may be an alternative. The most adequate timing and surgical position are chosen based on to the fetal gestational age and site of the pathology. CONCLUSIONS: Surgical treatments during pregnancy impose multiple medical and ethical problems. Timely diagnosis by MRI, careful clinical evaluation, and surgical treatment represent safe and effective procedures. Ongoing evolution of surgical, anesthesiological and obstetrical procedures results in favorable outcomes. However, interdisciplinary management and a wide knowledge of pregnancy-related pathologies are crucial for the best outcome for both mother and child.

Why clinical trials in disc regeneration strive to achieve completion: Insights from publication status and funding sources.

Background: Chronic discogenic low back pain (LBP) poses a significant global burden, yet effective therapeutic interventions directly targeting the underlying degenerative process remain elusive. After demonstrating promising results in preclinical studies, intradiscal injection of cell-based treatments has been increasingly investigated in the clinical setting. However, most clinical trials failed to reach publication, with the few available reports showing only minor improvements. The aim of this study was to analyze the prospective clinical trials registered on ClinicalTrials.gov investigating cell therapies for LBP, with a specific emphasis on identifying critical obstacles hindering study completion, including trial design and funding sources. Methods: A systematic search of prospective clinical trials investigating cell-based treatments for chronic LBP due to intervertebral disc degeneration was performed on ClinicalTrials.gov. Extracted data encompassed study design, recruitment, experimental treatment modalities, investigated outcomes, current status, completion date, publication status, and funding sources. Fisher's exact test assessed associations between categorical variables, while a multiple logistic regression model aimed to identify factors potentially linked to the publication status of the studies. Results: Our search identified 26 clinical trials. Among these, only 7 (26.9%) were published, and none of the other studies marked as completed reported any results on ClinicalTrials.gov. Fifty percent of included trials were funded by universities, whereas the rest was sponsored by industry (38.5%) or private institutions (11.5%). Experimental treatments primarily involved cell-based or cell-derived products of varying sources and concentrations. Products containing carriers, such as hyaluronic acid or fibrin, were more frequently funded by industry and private organizations (p = 0.0112). No significant differences emerged when comparing published and nonpublished studies based on funding, as well as between publication status and other variables. Conclusion: Most clinical trials exploring cell-based disc regenerative therapies for chronic LBP have never reached completion, with only a small fraction reporting preliminary data in publications.

Higher Accuracy and Better Clinical Outcomes in Navigated Thoraco-Lumbar Pedicle Screw Fixation versus Conventional Techniques: A Systematic Review and Meta-analysis.

STUDY DESIGN: Systematic review and meta-analysis. OBJECTIVE: This study aims to compare pedicle screw accuracy, clinical outcomes, and complications between navigated and conventional techniques. SUMMARY OF BACKGROUND DATA: In the last decades, intraoperative navigation has been introduced in spinal surgery to prevent risks and complications. METHODS: The search was executed on Cochrane Central Library, PubMed and Scopus on 30 April 2023. Randomized controlled trials, prospective and retrospective studies that compared pedicle screw accuracy in the thoracic-lumbar-sacral segments, blood loss, operative time, hospital stay, intraoperative and postoperative revision of screws, neurological and systemic complications, Visual Analogue Scale (VAS), and Oswestry Disability Index (ODI) between navigated and freehand or fluoroscopy-assisted techniques were included in this study. The meta-analysis was performed using Review Manager software. Clinical outcomes were assessed as continuous outcomes with mean difference, while pedicle screw accuracy and complications were assessed as dichotomous outcomes with odds ratio, all with 95% confidence intervals. The statistical significance of the results was fixed at P<0.05. RESULTS: This meta-analysis included 30 studies for a total of 17911 patients and 24600 pedicle screws. Statistically significant results in favour of the navigated technique were observed for accuracy of pedicle screws (P=0.0001), hospital stay (P=0.0002), blood loss (P<0.0001), postoperative revision of pedicle scews (P<0.00001), and systemic complications (P=0.0008). In particular, the positioning of the screws was clinically acceptable in 96.2% of the navigated group, and 94.2% with traditional techniques. No significant differences were found in VAS, ODI, and operative time between the two groups. CONCLUSION: Navigated pedicle screw fixation has been demonstrated to be a safe and effective technique with high improvement in clinical outcomes and accuracy in patients undergoing spinal fusion compared to conventional techniques. LEVEL OF EVIDENCE: III.

Importance of an Integrated Assessment of Functional Disability and Work Ability in Workers Affected by Low Back Pain.

Background: This study examines the relationship between functional disability and work ability in workers affected by low back pain (LBP) through an analysis of correlations between the Oswestry Disability Index (ODI) and Work Ability Index (WAI). The role of personal and work factors on functional disability/work ability levels has also been studied. LBP is the most common musculoskeletal problem and a major disabling health problem worldwide. Its etiology is multifactorial. Multidisciplinary approaches may help reduce the burden of pain and disability and improve job continuity and reintegration at work. Methods: A cohort of 264 patients affected by LBP from an Italian outpatient clinic were included in a clinical diagnostic/therapeutic trial aiming at rehabilitation and return to work through an integrated investigation protocol. Data were collected during the first medical examination using anamnestic and clinical tools. The final sample is composed of 252 patients, 57.1% man, 44.0 % blue collars, 46.4% with the high school degree, 45.6% married. Results: WAI and ODI reported a negative and fair correlation (r = -0.454; p = .000). Workers with acute LBP symptoms have a higher probability of severe disability than those with chronic LBP symptoms. White collars without depressive symptoms reported higher work ability - even in chronic disability conditions-than those with depressive symptoms. Conclusion: The study found that ODI and WAI have a convergent validity and this suggests that the two tools measure capture distinctive aspects of disability related to personal, environmental, and occupational characteristics. The most important and modifiable prognostic factors found for ODI and WAI were depressive symptoms, workday absence, and intensity of back pain. The study also found a mild association between age and ODI. The study's findings highlight the importance of using a multidisciplinary approach to manage and prevent disability due to LBP.

Intraoperative Cone-Beam Computed Tomography Navigation Versus 2-Dimensional Fluoroscopy in Single-Level Lumbar Spinal Fusion: A Comparative Analysis.

OBJECTIVE: Several studies have advocated for the higher accuracy of transpedicular screw placement under cone-beam computed tomography (CBCT) compared to conventional 2-dimensional (2D) fluoroscopy. The superiority of navigation systems in perioperative and postoperative outcomes remains a topic of debate. This study aimed to compare operative time, screw placement time and accuracy, total radiation dose, perioperative and postoperative outcomes in patients who underwent transpedicular screw fixation for degenerative lumbar spondylolisthesis (DLS) using intraoperative CBCT navigation versus 2D fluoroscopy. METHODS: A retrospective analysis was conducted on patients affected by single-level DLS who underwent posterior lumbar instrumentation with transpedicular screw fixation using surgical CBCT navigation (NV group) or 2D fluoroscopy-assisted freehand technique (FH group). Demographics, screw placement time and accuracy, operative time, total radiation dose, intraoperative blood loss, screw revision rate, complications, and length of stay (LOS) were assessed. RESULTS: The study included a total of 30 patients (NV group: n = 15; FH group: n = 15). The mean screw placement time, operative time, and LOS were significantly reduced in the NV group compared to the FH group (p < 0.05). The total radiation dose was significantly higher in the NV group (p < 0.0001). No significant difference was found in terms of blood loss and postoperative complications. CONCLUSION: This study suggests that intraoperative CBCT-navigated single-level lumbar transpedicular screw fixation is superior in terms of mean screw placement time, operative time, and LOS compared to 2D fluoroscopy, despite a higher intraoperative radiation exposure.

Rehabilitation of sick-listed LBP patients in occupational health with collaboration of the workplace.

The aim was to evaluate if rehabilitation procedures including occupational health (OH) and workplace participation increase return to work (RTW) rates among patients with subacute and chronic low back pain (LBP). A systematic review of randomized controlled trials was conducted using the PubMed and Cochrane databases. Main outcomes were RTW and days of sick leave. Interventions needed to be multidisciplinary including both OH and active workplace involvement in rehabilitation. Out of 1073 potentially eligible references, 8 met the inclusion criteria. Three studies had OH and 5 case managers involved in rehabilitation. Rehabilitation involving both OH and workplace improved RTW and decreased the number of sick leave days among LBP patients. Having case managers involved had no effect in RTW. In order to improve RTW, workplace visits and work ability meetings (WAMs) between OH and workplace are essential components in the rehabilitation process among patients with chronic LBP. Based on the study results, the authors suggest utilizing these co-operative interventions with workplaces in OH. High quality research investigating only the effect of WAMs in OH setting is needed in future. Int J Occup Med Environ Health. 2024;37(1):3-17.

Threats and opportunities of using ChatGPT in scientific writing-The risk of getting spineless.

ChatGPT and AI chatbots are revolutionizing several science fields, including medical writing. However, the inadequate use of such advantageous tools can raise numerous methodological and ethical issues.

The importance of psoas muscle on low back pain: a single-center study on lumbar spine MRI.

Background: Low back pain (LBP) is the most frequent indication to magnetic resonance imaging (MRI) examinations of the lumbosacral spine. The individual role of soft tissues, including muscles, on LBP is not fully understood and the contribution of each MRI-derived parameter of soft tissues status on the intensity of LBP has not been investigated in detail. Methods: The study design was observational retrospective, single center carried out at a University Hospital. Images were acquired using a using a 1.5 Tesla scanner. Patients completed a symptom questionnaire and rated their pain intensity using the Visual Analogue Scale (VAS). The VAS scores ​​were categorized as mild, moderate, and severe using cutoff values of 3.8 and 5.7, based on the literature. Biometric data, including weight and height, were also recorded to calculate the body mass index (BMI). The ratios between intramuscular fat infiltration and net muscle area were also calculated. Patient sample included 94 patients with LBP underwent MRI of the lumbosacral spine. Results: The stepwise analysis revealed that increasing psoas net area was associated with lower VAS levels (odds ratio [OR]: 0.94: 95% confidence interval [CI]: 0.90-0.98; p=.005), and an increase of one square centimeter of total psoas area resulted in a greater probability of reporting a mild (+1.21%; 95% CI: 0.37, 2.05%) or a moderate VAS (+0.40%; 95% CI: -0.02, 0.82%), Furthermore, a more severe VAS was associated with a higher BMI (OR: 1.13; 95% CI: 1.00-1.27). Conclusion: Our study demonstrates a relationship between LBP and MRI parameters of paravertebral and psoas muscles status. The psoas muscle is extremely important for spine stabilization and is linked to clinical symptoms of patients affected by LBP. These findings could contribute to future studies and improve treatment options in patients with LBP, possibly reducing the impact on disability, quality of life and socioeconomical burden.

Wharton's Jelly mesenchymal stromal cell-derived extracellular vesicles promote nucleus pulposus cell anabolism in an in vitro 3D alginate-bead culture model.

Background: Intradiscal transplantation of mesenchymal stromal cells (MSCs) has emerged as a promising therapy for intervertebral disc degeneration (IDD). However, the hostile microenvironment of the intervertebral disc (IVD) may compromise the survival of implanted cells. Interestingly, studies reported that paracrine factors, such as extracellular vesicles (EVs) released by MSCs, may regenerate the IVD. The aim of this study was to investigate the therapeutic effects of Wharton's Jelly MSC (WJ-MSC)-derived EVs on human nucleus pulposus cells (hNPCs) using an in vitro 3D alginate-bead culture model. Methods: After EV isolation and characterization, hNPCs isolated from surgical specimens were encapsulated in alginate beads and treated with 10, 50, and 100 µg/mL WJ-MSC-EVs. Cell proliferation and viability were assessed by flow cytometry and live/dead staining. Nitrite and glycosaminoglycan (GAG) content was evaluated through Griess and 1,9-dimethylmethylene blue assays. hNPCs in alginate beads were paraffin-embedded and stained for histological analysis (hematoxylin-eosin and Alcian blue) to assess extracellular matrix (ECM) composition. Gene expression levels of catabolic (MMP1, MMP13, ADAMTS5, IL6, NOS2), anabolic (ACAN), and hNPC marker (SOX9, KRT19) genes were analyzed through qPCR. Collagen type I and type II content was assessed with Western blot analysis. Results: Treatment with WJ-MSC-EVs resulted in an increase in cell content and a decrease in cell death in degenerated hNPCs. Nitrite production was drastically reduced by EV treatment compared to the control. Furthermore, proteoglycan content was enhanced and confirmed by Alcian blue histological staining. EV stimulation attenuated ECM degradation and inflammation by suppressing catabolic and inflammatory gene expression levels. Additionally, NPC phenotypic marker genes were also maintained by the EV treatment. Conclusions: WJ-MSC-derived EVs ameliorated hNPC growth and viability, and attenuated ECM degradation and oxidative stress, offering new opportunities for IVD regeneration as an attractive alternative strategy to cell therapy, which may be jeopardized by the harsh microenvironment of the IVD.

Exploring Borate-Modified Calcium Phosphate Ceramics: Antimicrobial Potential and Cytocompatibility Assessment.

Addressing periprosthetic infections, which present significant healing challenges that often require revision surgeries, necessitates the development of novel antibacterial materials and implants. Current research focuses on creating materials that hinder bacterial adhesion, colonization, and proliferation in surrounding tissues. Boron (B)-containing compounds are known for their antibacterial properties and potential in bone metabolism for regenerative medicine. In this study, we synthesized B-containing tricalcium phosphate (0.3B-TCP) with 1.1 wt.% B content via precipitation from aqueous solutions and sintering at 1100 °C. X-ray diffraction confirmed the ceramic's primary crystalline phase as ß-TCP, with B evenly distributed according to energy-dispersive spectroscopy data. Electron paramagnetic resonance (EPR) data verified stable paramagnetic borate anions, indicating successful BO33- substitution for phosphate groups. The microstructural properties of 0.3B-TCP ceramic were assessed before and after soaking in a saline solution. Its bending strength was approximately 30 MPa, and its porosity was about 33%. 0.3B-TCP ceramic demonstrated significant antimicrobial efficacy against various bacterial strains and a fungus. Cytotoxicity evaluation using equine adipose tissue-derived mesenchymal stem cells and osteogenic differentiation assessment were conducted. The combination of antibacterial efficacy and good cytocompatibility suggests 0.3B-TCP ceramic as a promising bone substitute material.

Functional Tests Predicting Return to Work of Workers with Non-Specific Low Back Pain: Are There Any Validated and Usable Functional Tests for Occupational Health Services in Everyday Practice? A Systematic Review.

The literature predominantly advocates subjective perception of disability and pain as an outcome measure for the functional evaluation of patients with low back pain (LBP). Physical outcome measurements are almost completely ignored. In this systematic review, we focused on physical functional measurements that can contribute to the prediction of patients' return to work (RTW) readiness after sick leave or rehabilitation. Searches were conducted in July 2022 without any time limit in the Cochrane Library, PEDro, PubMed and Scopus databases for functional and clinical tests reliable and applicable in clinical practice without demanding equipment. Two independent researchers extracted the data from the included articles in a standardised data collection form, and a third researcher validated the data extraction. No date restriction was applied. We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines in conducting the review. We found seven original articles, including six with an impact on predicting RTW. We found four fair and three poor original studies fulfilling our criteria. We found the Back Performance Scale (BPS) and back endurance test to be the most promising tests for occupational health service and the clinical practitioner. Radiation of back pain, with or without neurological deficiencies, had some predictive value in terms of RTW, too. The working conditions vary a lot, which causes inconsistency in the studies and in their interpretation. Functional tests could complete the widely used working ability evaluations methods such as the Work Ability Index (WAI) and are worth considering for future research. Overall, more research is needed in this field. The question of when LBP patients can resume everyday activities and work is not possible to determine with functional tests alone. Psychosocial aspects and work demands must be considered. PROSPERO: CRD42022353955. The study was funded by the University of Helsinki.

Oil-Water Emulsion Flocculation through Chitosan Desolubilization Driven by pH Variation.

Water pollution is a major concern in our modern age. The contamination of water, as a valuable and often limited resource, affects both the environment and human health. Industrial processes such as food, cosmetics, and pharmaceutical production also contribute to this problem. Vegetable oil production, for example, generates a stable oil/water emulsion containing 0.5-5% oil, which presents a difficult waste disposal issue. Conventional treatment methods based on aluminum salts generate hazardous waste, highlighting the need for green and biodegradable coagulant agents. In this study, the efficacy of commercial chitosan, a natural polysaccharide derived from chitin deacetylation, has been evaluated as a coagulation agent for vegetable oil emulsions. The effect of commercial chitosan was assessed in relation to different surfactants (anionic, cationic, and nonpolar) and pH levels. The results demonstrate that chitosan is effective at concentrations as low as 300 ppm and can be reused, providing a cost-effective and sustainable solution for oil removal. The flocculation mechanism relies on the desolubilization of the polymer, which acts as a net to entrap the emulsion, rather than solely relying on electrostatic interactions with the particles. This study highlights the potential of chitosan as a natural and ecofriendly alternative to conventional coagulants for the remediation of oil-contaminated water.

Effect of Irisin on Human Nucleus Pulposus Cells: New Insights into the Biological Cross-talk Between Muscle and Intervertebral Disk.

STUDY DESIGN: In vitro study. OBJECTIVE: To investigate the effect of irisin on human nucleus pulposus cells (hNPCs) in vitro. SUMMARY OF BACKGROUND DATA: Physical exercise (PE) favours weight loss and ameliorates function in patients with low back pain. Although there is no biological evidence that the intervertebral disk (IVD) can respond to PE, recent studies have shown that running is associated with increased IVD hydration and hypertrophy. Irisin, a myokine released upon muscle contraction, has demonstrated anabolic effects on different cell types, including chondrocytes. MATERIALS AND METHODS: hNPCs were exposed to 5, 10, and 25 ng/mL irisin. Cell proliferation, glycosaminoglycan (GAG) content, metabolic activity, gene expression of collagen type II (COL2), matrix metalloproteinase (MMP)-13, tissue inhibitor of matrix metalloproteinase (TIMP)-1 and TIMP-3, aggrecan (ACAN), interleukin (IL)-1ß, a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS)-5 were assessed. In addition, MTT assay and ADAMTS-5, COL2, TIMP-1, and IL-1ß gene expression were evaluated following incubation with irisin for 24 hours and subsequent culture with 10 ng/mL IL-1ß and vice versa (incubation for 24 hours with IL-1ß and subsequent culture with irisin). RESULTS: Irisin increased hNPC proliferation, metabolic activity, and GAG content, as well as COL2, ACAN, TIMP-1 and TIMP-3 gene expression, while decreasing MMP-13 and IL-1ß mRNA levels. Irisin pretreatment of hNPCs cultured in proinflammatory conditions resulted in a rescue of metabolic activity and a decrease of IL-1ß levels. Similarly, incubation of hNPCs with IL-1ß and subsequent exposure to irisin led to an increment of metabolic activity, COL2 gene expression, and a reduction of IL-1ß and ADAMTS-5 levels. CONCLUSIONS: Irisin increases hNPC proliferation, GAG content, metabolic activity, and promotes anabolic gene expression while reducing catabolic markers. Irisin may be one of the mediators by which PE and muscle tissues modulate IVD metabolism, suggesting the existence of a biological cross-talk between the muscle and IVD.

Micro-fragmented and nanofat adipose tissue derivatives: In vitro qualitative and quantitative analysis.

Introduction: Adipose tissue is widely exploited in regenerative medicine thanks to its trophic properties, mainly based on the presence of adipose-derived stromal cells. Numerous devices have been developed to promote its clinical use, leading to the introduction of one-step surgical procedures to obtain minimally manipulated adipose tissue derivatives. However, only a few studies compared their biological properties. This study aimed to characterize micro-fragmented (MAT) and nanofat adipose tissue (NAT) obtained with two different techniques. Methods: MAT, NAT and unprocessed lipoaspirate were collected from surgical specimens. RNA extraction and collagenase isolation of stromal vascular fraction (SVF) were performed. Tissue sections were analysed by histological and immunohistochemical (collagen type I, CD31, CD34 and PCNA) staining to assess tissue morphology and cell content. qPCR was performed to evaluate the expression of stemness-related (SOX2, NANOG and OCT3/4), extracellular matrix (COL1A1) and inflammatory genes (IL1ß, IL6 and iNOS). Furthermore, multilineage differentiation was assessed following culture in adipogenic and osteogenic media and staining with Oil Red O and Alizarin red. ASC immunophenotype was assessed by flow cytometric analysis of CD90, CD105, CD73 and CD45. Results: Histological and immunohistochemical results showed an increased amount of stroma and a reduction of adipocytes in MAT and NAT, with the latter displaying the highest content of collagen type I, CD31, CD34 and PCNA. From LA to MAT and NAT, an increasing expression of NANOG, SOX2, OCT3/4, COL1A1 and IL6 was noted, while no significant differences in terms of IL1ß and iNOS emerged. No statistically significant differences were noted between NAT and SVF in terms of stemness-related genes, while the latter demonstrated a significantly higher expression of stress-related markers. SVF cells derived from all three samples (LA, MAT, and NAT) showed a similar ASC immunoprofile as well as osteogenic and adipogenic differentiation. Discussion: Our results showed that both MAT and NAT techniques allowed the rapid isolation of ASC-rich grafts with a high anabolic and proliferative potential. However, NAT showed the highest levels of extracellular matrix content, replicating cells, and stemness gene expression. These results may provide precious clues for the use of adipose tissue derivatives in the clinical setting.

Mesenchymal stem cell-derived secretome enhances nucleus pulposus cell metabolism and modulates extracellular matrix gene expression in vitro.

Introduction: Intradiscal mesenchymal stromal cell (MSC) therapies for intervertebral disc degeneration (IDD) have been gaining increasing interest due to their capacity to ameliorate intervertebral disc metabolism and relieve low back pain (LBP). Recently, novel investigations have demonstrated that most of MSC anabolic effects are exerted by secreted growth factors, cytokines, and extracellular vesicles, collectively defined as their secretome. In this study, we aimed to evaluate the effect of bone-marrow-MSCs (BM-MSCs) and adipose-derived stromal cells (ADSCs) secretomes on human nucleus pulposus cells (hNPCs) in vitro. Methods: BM-MSCs and ADSCs were characterized according to surface marker expression by flow cytometry and multilineage differentiation by Alizarin red, Red Oil O and Alcian blue staining. After isolation, hNPCs were treated with either BM-MSC secretome, ADSC secretome, interleukin (IL)-1ß followed by BM-MSC secretome or IL-1ß followed by ADSC secretome. Cell metabolic activity (MTT assay), cell viability (LIVE/DEAD assay), cell content, glycosaminoglycan production (1,9-dimethylmethylene blue assay), extracellular matrix and catabolic marker gene expression (qPCR) were assessed. Results: 20% BM-MSC and ADSC secretomes (diluted to normal media) showed to exert the highest effect towards cell metabolism and were then used in further experiments. Both BM-MSC and ADSC secretomes improved hNPC viability, increased cell content and enhanced glycosaminoglycan production in basal conditions as well as after IL-1ß pretreatment. BM-MSC secretome significantly increased ACAN and SOX9 gene expression, while reducing the levels of IL6, MMP13 and ADAMTS5 both in basal conditions and after in vitro inflammation with IL-1ß. Interestingly, under IL-1ß stimulation, ADSC secretome showed a catabolic effect with decreased extracellular matrix markers and increased levels of pro-inflammatory mediators. Discussion: Collectively, our results provide new insights on the biological effect of MSC-derived secretomes on hNPCs, with intriguing implications on the development of cell-free approaches to treat IDD.