Safety and Tolerability of Stromal Vascular Fraction Combined with β-Tricalcium Phosphate in Posterior Lumbar Interbody Fusion: Phase I Clinical Trial

Analyzing the Clinical Potential of Stromal Vascular Fraction: A Comprehensive Literature Review

Background: Regenerative medicine is evolving with discoveries like the stromal vascular fraction (SVF), a diverse cell group from adipose tissue with therapeutic promise. Originating from fat cell metabolism studies in the 1960s, SVF's versatility was recognized after demonstrating multipotency. Comprising of cells like pericytes, smooth muscle cells, and, notably, adipose-derived stem cells (ADSCs), SVF offers tissue regeneration and repair through the differentiation and secretion of growth factors. Its therapeutic efficacy is due to these cells' synergistic action, prompting extensive research. Methods: This review analyzed the relevant literature on SVF, covering its composition, action mechanisms, clinical applications, and future directions. An extensive literature search from January 2018 to June 2023 was conducted across databases like PubMed, Embase, etc., using specific keywords. Results: The systematic literature search yielded a total of 473 articles. Sixteen articles met the inclusion criteria and were included in the review. This rigorous methodology provides a framework for a thorough and systematic analysis of the existing literature on SVF, offering robust insights into the potential of this important cell population in regenerative medicine. Conclusions: Our review reveals the potential of SVF, a heterogeneous cell mixture, as a powerful tool in regenerative medicine. SVF has demonstrated therapeutic efficacy and safety across disciplines, improving pain, tissue regeneration, graft survival, and wound healing while exhibiting immunomodulatory and anti-inflammatory properties.

Evaluating the quality of studies reporting on clinical applications of stromal vascular fraction: A systematic review and proposed reporting guidelines (CLINIC-STRA-SVF)

Background

The stromal vascular fraction (SVF) has been widely explored in a number of therapeutic applications in several specialties. Its therapeutic potential is being increasingly demonstrated, although its mechanism of action is still unclear.

Objective

To evaluate the quality of studies reporting on clinical applications of SVF.

Method

This is a systematic literature review that followed the PRISMA guidelines with the search of the studies from December 1, 2012, to December 1, 2022, in the following databases: MEDLINE, LILACS and EMBASE. The level of evidence of the studies was assessed using the GRADE system, and the rigor used in the publication of the results was assessed in relation to adherence to the guidelines indicated by the EQUATOR Network Group. The CLINIC - STRA-SVF reporting guideline was developed after the completion of this systematic review.

Results

A total of 538 articles were found, and 77 articles were selected after reading the titles and abstracts and removing duplicates. Then, 15 studies were removed for not meeting the inclusion criteria, leaving 62 studies. The CLINIC - STRA-SVF was developed and consists of 33 items and two tables.

Conclusion

There is scientific evidence, although mostly with a low level of evidence, that the use of SVF in clinical applications is safe and effective. The information published in these studies should be standardized, and the CLINIC - STRA-SVF reporting guideline proposed in this study may assist in the design, conduct, recording and reporting of clinical trials and others clinical studies involving the SVF.

Emerging Technologies within Spine Surgery

New innovations within spine surgery continue to propel the field forward. These technologies improve surgeons' understanding of their patients and allow them to optimize treatment planning both in the operating room and clinic. Additionally, changes in the implants and surgeon practice habits continue to evolve secondary to emerging biomaterials and device design. With ongoing advancements, patients can expect enhanced preoperative decision-making, improved patient outcomes, and better intraoperative execution. Additionally, these changes may decrease many of the most common complications following spine surgery in order to reduce morbidity, mortality, and the need for reoperation. This article reviews some of these technological advancements and how they are projected to impact the field. As the field continues to advance, it is vital that practitioners remain knowledgeable of these changes in order to provide the most effective treatment possible.

Bone Regeneration Using Mesenchymal Stromal Cells and Biocompatible Scaffolds: A Concise Review of the Current Clinical Trials

Bone regenerative medicine is a clinical approach combining live osteoblast progenitors, such as mesenchymal stromal cells (MSCs), with a biocompatible scaffold that can integrate into host bone tissue and restore its structural integrity. Over the last few years, many tissue engineering strategies have been developed and thoroughly investigated; however, limited approaches have been translated to clinical application. Consequently, the development and clinical validation of regenerative approaches remain a centerpiece of investigational efforts towards the clinical translation of advanced bioengineered scaffolds. The aim of this review was to identify the latest clinical trials related to the use of scaffolds with or without MSCs to regenerate bone defects. A revision of the literature was performed in PubMed, Embase, and Clinicaltrials.gov from 2018 up to 2023. Nine clinical trials were analyzed according to the inclusion criteria: six presented in the literature and three reported in Clinicaltrials.gov. Data were extracted covering background trial information. Six of the clinical trials added cells to scaffolds, while three used scaffolds alone. The majority of scaffolds were composed of calcium phosphate ceramic alone, such as β-tricalcium phosphate (TCP) (two clinical trials), biphasic calcium phosphate bioceramic granules (three clinical trials), and anorganic bovine bone (two clinical trials), while bone marrow was the primary source of the MSCs (five clinical trials). The MSC expansion was performed in GMP facilities, using human platelet lysate (PL) as a supplement without osteogenic factors. Only one trial reported minor adverse events. Overall, these findings highlight the importance and efficacy of cell-scaffold constructs in regenerative medicine under different conditions. Despite the encouraging clinical results obtained, further studies are needed to assess their clinical efficacy in treating bone diseases to optimize their application.

Intraoperative Administration of Adipose Stromal Vascular Fraction Does Not Improve Functional Outcomes in Young Patients with Anterior Cruciate Ligament Reconstruction

Adipose stromal vascular fraction (SVF) has a versatile cellular system for biologically augmented therapies. However, there have been no clinical studies investigating the benefits of the augmentation of anterior cruciate ligament reconstruction (ACLR) with SVF. We conducted a retrospective study in assessing the effects of intraoperative SVF administration on the functional outcomes in young patients with ACLR. The enrolled patients were divided into the control group (ACLR only) and the SVF group (ACLR with SVF). The functional outcomes in both groups were assessed by the Lysholm knee scoring system, the Tegner activity scale, and the International Knee Documentation Committee (IKDC) subjective evaluation form, and compared at several time points during a 12-month follow-up. We found that the sex distribution and pre-surgery scores were similar in the two groups, whereas the mean age of the SVF group was higher than that of the control group (p = 0.046). The between-group analysis and generalized estimating equation model analysis revealed that, while patients in the SVF group significantly improved all their functional outcomes at 12 months after surgery, this improvement was not significantly different from the results of patients in the control group (Lysholm, p = 0.553; Tegner, p = 0.197; IKDC, p = 0.486). No side effects were observed in either group. We concluded that the intraoperative administration of SVF does not improve or accelerate functional recovery after ACLR in young patients.

Therapeutic effect of adipose stromal vascular fraction spheroids for partial bladder outlet obstruction induced underactive bladder

BACKGROUND

Underactive bladder (UAB) is a common clinical problem but related research is rarely explored. As there are currently no effective therapies, the administration of adipose stromal vascular fraction (ad-SVF) provides a new potential method to treat underactive bladder.

METHODS

Male Sprague-Dawley rats were induced by partial bladder outlet obstruction (PBOO) for four weeks and randomly divided into three groups: rats treated with PBS (Sham group); rats administrated with ad-SVF (ad-SVF group) and rats performed with ad-SVF spheroids (ad-SVFsp group). After four weeks, urodynamic studies were performed to evaluate bladder functions and all rats were sacrificed for further studies.

RESULTS

We observed that the bladder functions and symptoms of UAB were significantly improved in the ad-SVFsp group than that in the Sham group and ad-SVF group. Meanwhile, our data showed that ad-SVF spheroids could remarkably promote angiogenesis, suppress cell apoptosis and stimulate cell proliferation in bladder tissue than that in the other two groups. Moreover, ad-SVF spheroids increased the expression levels of bFGF, HGF and VEGF-A than ad-SVF. IVIS Spectrum small-animal in vivo imaging system revealed that ad-SVF spheroids could increase the retention rate of transplanted cells in bladder tissue.

CONCLUSIONS

Ad-SVF spheroids improved functions and symptoms of bladder induced by PBOO, which contributes to promote angiogenesis, suppress cell apoptosis and stimulate cell proliferation. Ad-SVF spheroids provide a potential treatment for the future patients with UAB.

Current Biomaterial-Based Bone Tissue Engineering and Translational Medicine

Bone defects cause significant socio-economic costs worldwide, while the clinical "gold standard" of bone repair, the autologous bone graft, has limitations including limited graft supply, secondary injury, chronic pain and infection. Therefore, to reduce surgical complexity and speed up bone healing, innovative therapies are needed. Bone tissue engineering (BTE), a new cross-disciplinary science arisen in the 21st century, creates artificial environments specially constructed to facilitate bone regeneration and growth. By combining stem cells, scaffolds and growth factors, BTE fabricates biological substitutes to restore the functions of injured bone. Although BTE has made many valuable achievements, there remain some unsolved challenges. In this review, the latest research and application of stem cells, scaffolds, and growth factors in BTE are summarized with the aim of providing references for the clinical application of BTE.