Application of buccal fat pad-derived stem cells in combination with autogenous iliac bone graft in the treatment of maxillomandibular atrophy: a preliminary human study

Bone Regeneration with Mesenchymal Stem Cells in Scaffolds: Systematic Review of Human Clinical Trials

The aim of the study is to determine the effectiveness of stem cells in scaffolds in the treatment of bone deficits, in regard of bone regeneration, safety, rehabilitation and quality of life in humans. The systematic review was conducted in accordance with PRISMA 2020. A systematic search was conducted in three search engines and two registries lastly in 29-9-2022.for studies of the last 15 years. The risk of bias was assessed with RoB-2, ROBINS- I and NIH Quality of Before-After (Pre-Post) Studies with no Control group. The certainty of the results was assessed with the GRADE assessment tool. Due to heterogeneity, the results were reported in tables, graphs and narratively. The study protocol was published in PROSPERO with registration number CRD42022359049. Of the 10,091 studies retrieved, 14 were meeting the inclusion criteria, and were qualitatively analyzed. 138 patients were treated with mesenchymal stem cells in scaffolds, showing bone healing in all cases, and even with better results than the standard care. The adverse events were mild in most cases and in accordance with the surgery received. When assessed, there was a rehabilitation of the deficit and a gain in quality of life was detected. Although the heterogeneity between the studies and the small number of patients, the administration of mesenchymal stem cells in scaffolds seems safe and effective in the regeneration of bone defects. These results pave the way for the conduction of more clinical trials, with greater number of participants, with more standardized procedures.

Effect of buccal fat autotransplantation on improving the alveolar socket bone regeneration: An in-vivo study

Background

There are various materials used for socket preservation following dental extraction. The aim of the present animal study was to histologically investigate the efficacy of buccal fat autotransplantation on alveolar bone regeneration following dental extraction.

Study design

In this prospective, double-blind laboratory experiment with a split-mouth design, 16 mandibular second premolar teeth in eight beagle dogs were extracted, and half of the extraction sockets were randomly filled using buccal fat autotransplantation. Other samples were left untouched to heal normally by the formed blood clot. Buccal fat autotransplantation was the primary predictor variable, and the type and amount of newly formed bone were the primary outcome variables. Assessment methods were the H & E coloring technique and histomorphometric evaluation. The significance level was set at 0.05, and data was subjected to Chi-Square and Wilcoxon signed-rank tests using SAS statistical software version 9.4.

Results

From the total number of 16 samples in 8 dogs, 50% of the samples in the intervention group represented inflammation with lower intensity compared to 33% in the control group; however, this difference was not considered statistically significant (Chi-Square test, P-value = 0.55). Wilcoxon test results showed no statistically significant difference between the two groups regarding the mean amount of total bone formation (Z = 0.00, P-value = 1.00).

Conclusion

It was inferred from the outcomes of the present study that when compared to the normal healing of the socket, buccal fat autotransplantation did not represent with superior outcome concerning the socket bone regeneration.

Buccal Mesenchymal Stromal Cells as a Source of Osseointegration of Titanium Implants

We studied the interaction of human buccal mesenchymal stem cells (MSCs) and osteoblasts differentiated from them with the surface of titanium samples. MSCs were isolated by enzymatic method from buccal fat pads. The obtained cell culture was presented by MSCs, which was confirmed by flow cytometry and differentiation into adipocytes and osteoblasts. Culturing of buccal MSCs on titanium samples was accompanied by an increase in the number of cells for 15 days and the formation of a developed network of F-actin fibers in the cells. The viability of buccal MSCs decreased by 8 days, but was restored by 15 days. Culturing of osteoblasts obtained as a result of buccal MSC differentiation on the surface of titanium samples was accompanied by a decrease in their viability and proliferation. Thus, MSCs from buccal fat pads can be used to coat implants to improve osseointegration during bone reconstruction in craniofacial surgery and dentistry. To improve the integration of osteoblasts, modification of the surface of titanium samples is required.

Effects of Oral Cavity Stem Cell Sources and Serum-Free Cell Culture on Hydrogel Encapsulation of Mesenchymal Stem Cells for Bone Regeneration: An In Vitro Investigation

INTRODUCTION

To develop a stem cell delivery model and improve the safety of stem cell transplantation for bone regeneration, this study aimed to determine the effects of stem cell sources, serum-free cell culture, and hydrogel cell encapsulation on the growth and osteogenic differentiation of mesenchymal stem cells (MSCs) from the oral cavity.

METHODS

The study groups were categorized according to stem cell sources into buccal fat pad adipose (hBFP-ADSCs) (Groups 1, 4, and 7), periodontal ligament (hPDLSCs) (Groups 2, 5, and 8), and dental pulp-derived stem cells (hDPSCs) (Groups 3, 6, and 9). MSCs from each source were isolated and expanded in three types of sera: fetal bovine serum (FBS) (Groups 1-3), human serum (HS) (Groups 4-6), and synthetic serum (SS) (StemPro™ MSC SFM) (Groups 7-9) for monolayer (m) and hydrogel cell encapsulation cultures (e). Following this, the morphology, expression of MSC cell surface antigens, growth, and osteogenic differentiation potential of the MSCs, and the expression of adhesion molecules were analyzed and compared.

RESULTS

SS decreased variations in the morphology and expression levels of cell surface antigens of MSCs from three cell sources (Groups 7m-9m). The levels of osteoblastic differentiation of the hPDLSCs and hBFP-ADSCs were increased in SS (Groups 8m and 7m) and the cell encapsulation model (Groups 1e, 4e, 7e-9e), but the promoting effects of SS were decreased in a cell encapsulation model (Groups 7e-9e). The expression levels of the alpha v beta 3 (ITG-αVβ3) and beta 1 (ITG-β1) integrins in the encapsulated cells in FBS (Group 1e) were higher than those in the SS (Group 7e).

CONCLUSIONS

Human PDLSCs and BFP-ADSCs were the optimum stem cell source for stem cell encapsulation by using nanohydroxyapatite-calcium carbonate microcapsule-chitosan/collagen hydrogel in serum-free conditions.

Bone Tissue Engineering Strategies for Alveolar Cleft: Review of Preclinical Results and Guidelines for Future Studies

The current standard of care for an alveolar cleft defect is an autogenous bone graft, typically from the iliac crest. Given the limitations of alveolar bone graft surgery, such as limited supply, donor site morbidity, graft failure, and need for secondary surgery, there has been growing interest in regenerative medicine strategies to supplement and replace traditional alveolar bone grafts. Though there have been preliminary clinical studies investigating bone tissue engineering methods in human subjects, lack of consistent results as well as limitations in study design make it difficult to determine the efficacy of these interventions. As the field of bone tissue engineering is rapidly advancing, reconstructive surgeons should be aware of the preclinical studies informing these regenerative strategies. We review preclinical studies investigating bone tissue engineering strategies in large animal maxillary or mandibular defects and provide an overview of scaffolds, stem cells, and osteogenic agents applicable to tissue engineering of the alveolar cleft. An electronic search conducted in the PubMed database up to December 2021 resulted in 35 studies for inclusion in our review. Most studies showed increased bone growth with a tissue engineering construct compared to negative control. However, heterogeneity in the length of follow up, method of bone growth analysis, and inconsistent use of positive control groups make comparisons across studies difficult. Future studies should incorporate a pediatric study model specific to alveolar cleft with long-term follow up to fully characterize volumetric defect filling, cellular ingrowth, bone strength, tooth movement, and implant support.

Using the Dermal Fat Graft as a Barrier Membrane in Unilateral Alveolar Cleft Grafting: A Randomized Clinical Trial

INTRODUCTION

Alveolar cleft grafting is a surgical procedure that usually suffers from inferior results.

METHODOLOGY

The patients were divided into 2 groups; study and control. In the study group, the grafted site was covered with a dermal fat graft.

RESULTS

Showed that the bone fill percentage (Bergland Scale) recorded in the study was significantly better ( P =0.03); the study group had 14 successful cases out of 18 compared with the control, which had only 9 out of 20. The study group significantly ( P = 0.002) better bone fill (71%±32%) compared with the control (46%±33%). There was a significant reduction in dehiscence in the study compared with the control ( P =0.02); the study group had no dehiscence compared with the control, which had 5 dehiscence.

CONCLUSION

The dermal fat graft use as a barrier membrane was successful in improving alveolar cleft grafting.

Potential of Oral Cavity Stem Cells for Bone Regeneration: A Scoping Review

Bone loss is a common problem that ranges from small defects to large defects after trauma, surgery, or congenital malformations. The oral cavity is a rich source of mesenchymal stromal cells (MSCs). Researchers have documented their isolation and studied their osteogenic potential. Therefore, the objective of this review was to analyze and compare the potential of MSCs from the oral cavity for use in bone regeneration.

METHODS

A scoping review was carried out following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) guidelines. The databases reviewed were PubMed, SCOPUS, Scientific Electronic Library Online (SciELO), and Web of Science. Studies using stem cells from the oral cavity to promote bone regeneration were included.

RESULTS

A total of 726 studies were found, of which 27 were selected. The MSCs used to repair bone defects were (I) dental pulp stem cells of permanent teeth, (II) stem cells derived from inflamed dental pulp, (III) stem cells from exfoliated deciduous teeth, (IV) periodontal ligament stem cells, (V) cultured autogenous periosteal cells, (VI) buccal fat pad-derived cells, and (VII) autologous bone-derived mesenchymal stem cells. Stem cells associate with scaffolds to facilitate insertion into the bone defect and to enhance bone regeneration. The biological risk and morbidity of the MSC-grafted site were minimal. Successful bone formation after MSC grafting has been shown for small defects with stem cells from the periodontal ligament and dental pulp as well as larger defects with stem cells from the periosteum, bone, and buccal fat pad.

CONCLUSIONS

Stem cells of maxillofacial origin are a promising alternative to treat small and large craniofacial bone defects; however, an additional scaffold complement is required for stem cell delivery.

Tissue buccal fat pad-stromal vascular fraction as a safe source in maxillofacial bone regeneration: A clinical pilot study

AIM

The purpose of this study was to examine the biological properties of the buccal fat pad (BFP)-derived tissue stromal vascular fraction (tSVF) in vitro and compare them with BFP-derived cellular SVF (cSVF). Furthermore, a clinical pilot study assessed the safety of using BFP-derived tSVF for maxillofacial bone regeneration.

MATERIALS AND METHODS

This study was performed in two sections: 1) experimental section: BFP tissue was harvested from three healthy donors, and then cSVF and tSVF were isolated by enzymatic and mechanical methods to assess their biological properties and 2) clinical section: Ten patients with maxillofacial bone defects were enrolled according to eligibility criteria and offered two options for surgery, including autologous BFP-tSVF (n = 5) and autologous bone grafting (n = 5), to evaluate safety after a year of follow-up.

RESULTS

The BFP-tSVF exhibited high cell viability and various cell surface markers, including CD45, CD31, and CD34. There was no population-doubling time and multilineage differentiation capacity compared with BFP-cSVF. BFP-tSVF is safe because of the lack of intervention-related adverse events reported in donor and surgery sites during a one-year period. In addition, cell therapy was feasible because it can be performed during surgery and requires little preparation time. Patients in the ABG group experienced pain and tenderness in the iliac crest, leading to dissatisfaction and complications.

CONCLUSION

The experimental results confirmed that the cells isolated from BFP-tSVF have stemness properties similar to BFP-cSVF. Clinical evaluation also indicated that this cellular product could be used safely to regenerate maxillofacial bone defects.

NIR irradiation of human buccal fat pad adipose stem cells and its effect on TRP ion channels

The effect of near infrared (NIR) laser irradiation on proliferation and osteogenic differentiation of buccal fat pad-derived stem cells and the role of transient receptor potential (TRP) channels was investigated in the current research. After stem cell isolation, a 940 nm laser with 0.1 W, 3 J/cm² was used in pulsed and continuous mode for irradiation in 3 sessions once every 48 h. The cells were cultured in the following groups: non-osteogenic differentiation medium/primary medium (PM) and osteogenic medium (OM) groups with laser-irradiated (L +), without irradiation (L -), laser treated + Capsazepine inhibitor (L + Cap), and laser treated + Skf96365 inhibitor (L + Skf). Alizarin Red staining and RT-PCR were used to assess osteogenic differentiation and evaluate RUNX2, Osterix, and ALP gene expression levels. The pulsed setting showed the best viability results (P < 0.05) and was used for osteogenic differentiation evaluations. The results of Alizarin red staining were not statistically different between the four groups. Osterix and ALP expression increased in the (L +) group. This upregulation abrogated in the presence of Capsazepine, TRPV1 inhibitor (L + Cap); however, no significant effect was observed with Skf96365 (L + Skf).

A Three-Dimensional Printed Polycaprolactone–Biphasic-Calcium-Phosphate Scaffold Combined with Adipose-Derived Stem Cells Cultured in Xenogeneic Serum-Free Media for the Treatment of Bone Defects

The efficacy of a three-dimensional printed polycaprolactone–biphasic-calcium-phosphate scaffold (PCL–BCP TDP scaffold) seeded with adipose-derived stem cells (ADSCs), which were cultured in xenogeneic serum-free media (XSFM) to enhance bone formation, was assessed in vitro and in animal models. The ADSCs were isolated from the buccal fat tissue of six patients using enzymatic digestion and the plastic adherence method. The proliferation and osteogenic differentiation of the cells cultured in XSFM when seeded on the scaffolds were assessed and compared with those of cells cultured in a medium containing fetal bovine serum (FBS). The cell–scaffold constructs were cultured in XSFM and were implanted into calvarial defects in thirty-six Wistar rats to assess new bone regeneration. The proliferation and osteogenic differentiation of the cells in the XSFM medium were notably better than that of the cells in the FBS medium. However, the efficacy of the constructs in enhancing new bone formation in the calvarial defects of rats was not statistically different to that achieved using the scaffolds alone. In conclusion, the PCL–BCP TDP scaffolds were biocompatible and suitable for use as an osteoconductive framework. The XSFM medium could support the proliferation and differentiation of ADSCs in vitro. However, the cell–scaffold constructs had no benefit in the enhancement of new bone formation in animal models.

Prefabrication technique by preserving a muscular pedicle from masseter muscle as an in vivo bioreactor for reconstruction of mandibular critical-sized bone defects in canine models

In vivo bioreactors serve as regenerative niches that improve vascularization and regeneration of bone grafts. This study has evaluated the masseter muscle as a natural bioreactor for βTCP or PCL/βTCP scaffolds, in terms of bone regeneration. The effect of pedicle preservation, along with sole, or MSC- or rhBMP2-combined application of scaffolds, has also been studied. Twenty-four mongrel dogs were randomly placed in six groups, including βTCP, βTCP/rhBMP2, βTCP/MSCs, PCL/βTCP, PCL/βTCP/rhBMP2, and PCL/βTCP/MSCs. During the first surgery, the scaffolds were implanted into the masseter muscle for being prefabricated. After 2 months, each group was divided into two subgroups prior to mandibular bone defect reconstruction; one with a preserved vascularized pedicle and one without. After 12 weeks, animals were euthanized, and new bone formation was evaluated using histological analysis. Histological analysis showed that all β-TCP scaffold groups had resulted in significantly greater rates of new bone formation, either with a pedicle surgical approach or non-pedicle surgical approach, comparing to their parallel groups of βTCP/PCL scaffolds (p ≤ .05). Pedicled β-TCP scaffold groups that were treated with either rhBMP2 (48.443% ± 0.250%) or MSCs (46.577% ± 0.601%) demonstrated the highest rates of new bone formation (p ≤ .05). Therefore, masseter muscle can be used as a local in vivo bioreactor with potential clinical advantages in reconstruction of human mandibular defects. In addition, scaffold composition, pedicle preservation, and treatment with MSCs or rhBMP2, influence new bone formation and scaffold degradation rates in the prefabrication technique.

Oral tissues regeneration using intraoral mesenchymal stem cells

Background

Oral pathologies or some treatments can cause facial and functional alterations, being fundament to retrieve those functions restoring the original anatomy of the lost tissues. On this purpose, various techniques have been studied, one of these was the tissue engineering. Mesenchymal stem cells (MSC) are multipotent adult stem cells. The MSC in the oral cavity have been striking for regenerative therapies by its high plasticity, good interaction with scaffolds and growth factors, good proliferation and differentiation, they are also easy to obtain. Objective: The objective of this study was to describe the current uses of the intraoral MSC for the regeneration of the tissues of the oral cavity.

Material and Methods

An electronic research was made in the databases PubMed, Cochrane Library, Google Scholar, Scopus and EBSCO between 2000 to 2018.

Results

21 articles were included. 13 were studies in vivo and 8 were studies in humans. The site mostly used as a giver site was the dental pulp. Intraoral MSC are able to regenerate the pulp dentin complex, alveolar bone and periodontium.

Conclusions

Intraoral MSC come from easy access areas, less traumatic interventions and have high potential to regenerate intraoral tissues in comparison to MSC from other sites of the body which allows a more predictable oral tissues regeneration.

Key words:Oral stem cells, oral cavity, regeneration, tissue engineering.

Comparison of osteogenic differentiation potential of induced pluripotent stem cells and buccal fat pad stem cells on 3D-printed HA/β-TCP collagen-coated scaffolds

Production of a 3D bone construct with high-yield differentiated cells using an appropriate cell source provides a reliable strategy for different purposes such as therapeutic screening of the drugs. Although adult stem cells can be a good source, their application is limited due to invasive procedure of their isolation and low yield of differentiation. Patient-specific human-induced pluripotent stem cells (hiPSCs) can be an alternative due to their long-term self-renewal capacity and pluripotency after several passages, resolving the requirement of a large number of progenitor cells. In this study, a new biphasic 3D-printed collagen-coated HA/β-TCP scaffold was fabricated to provide a 3D environment for the cells. The fabricated scaffolds were characterized by the 3D laser scanning digital microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and mechanical test. Then, the osteogenesis potential of the hiPSC-seeded scaffolds was investigated compared to the buccal fat pad stem cell (BFPSC)-seeded scaffolds through in vitro and in vivo studies. In vitro results demonstrated up-regulated expressions of osteogenesis-related genes of RUNX2, ALP, BMP2, and COL1 compared to the BFPSC-seeded scaffolds. In vivo results on calvarial defects in the rats confirmed a higher bone formation in the hiPSC-seeded scaffolds compared to the BFPSC-seeded groups. The immunofluorescence assay also showed higher expression levels of collagen I and osteocalcin proteins in the hiPSC-seeded scaffolds. It can be concluded that using the hiPSC-seeded scaffolds can lead to a high yield of osteogenesis, and the hiPSCs can be used as a superior stem cell source compared to BFPSCs for bone-like construct bioengineering.

Platelet-rich plasma counteracts detrimental effect of high-glucose concentrations on mesenchymal stem cells from Bichat fat pad

Diabetic patients display increased risk of periodontitis and failure in bone augmentation procedures. Mesenchymal stem cells (MSCs) and platelet-rich plasma (PRP) represent a relevant advantage in tissue repair process and regenerative medicine. We isolated MSCs from Bichat's buccal fat pad (BFP) and measured the effects of glucose and PRP on cell number and osteogenic differentiation potential. Cells were cultured in the presence of 5.5-mM glucose (low glucose [LG]) or 25-mM glucose (high glucose [HG]). BFP-MSC number was significantly lower when cells were cultured in HG compared with those in LG. Following osteogenic differentiation procedures, calcium accumulation, alkaline phosphatase activity, and expression of osteogenic markers were significantly lower in HG compared with LG. Exposure of BFP-MSC to PRP significantly increased cell number and osteogenic differentiation potential, reaching comparable levels in LG and in HG. Thus, high-glucose concentrations impair BFP-MSC growth and osteogenic differentiation. However, these detrimental effects are largely counteracted by PRP.

Improved bone regeneration through amniotic membrane loaded with buccal fat pad-derived MSCs as an adjuvant in maxillomandibular reconstruction

BACKGROUND

Human amniotic membranes (HAMs), as a biological membrane with healing, osteogenic, and cell therapy potential, has been in the spotlight to enhance the outcomes of treating bone defects. Present study aims to clinically assess the potential of HAM loaded with buccal fat pad-derived stem cells (BFSCs) as an osteogenic coverage for onlay bone grafts to maxillomandibular bone defects.

MATERIALS AND METHODS

Nine patients with jaw bone defects were enrolled in the present study. The patients were allocated to two study groups: Iliac crest bone graft with HAM coverage (n = 5), and Iliac bone grafts covered with HAM loaded with BFSCs (n = 4). Five months following the grafting and prior to implant placement, cone beam computed tomography was performed for radiomorphometric analysis.

RESULTS

The mean increase in bone width was found to be significantly greater in the HAM + BFSCs group (4.42 ± 1.03 mm versus 3.07 ± 0.73 mm, p < 0.05). Further, the changes in vertical dimension were greater in the HAM + BFSCs group (4.66 ± 1.06 mm versus 4.14 ± 1.03 mm, p > 0.05).

CONCLUSION

Combined use of HAM with mesenchymal stem cells may enhance bone regeneration specifically in the horizontal dimension. Moreover, this methodology reduces the amount of harvested autogenous bone and diminish secondary bone resorption.

Buccal fat pad-derived stem cells with anorganic bovine bone mineral scaffold for augmentation of atrophic posterior mandible: An exploratory prospective clinical study

BACKGROUND

Application of adipose-derived stem cells originated from buccal fat pad (BFP) can simplify surgical procedures and diminish clinical risks compared to large autograft harvesting.

PURPOSE

This study sought to evaluate and compare the efficacy of buccal fat pad-derived stem cells (BFPSCs) in combination with anorganic bovine bone mineral (ABBM) for vertical and horizontal augmentation of atrophic posterior mandibles.

MATERIALS AND METHODS

Fourteen patients with atrophic posterior mandible were elected for this prospective exploratory study. BFP (3-5 mL) was harvested and BFPSCs were isolated and combined with ABBM at 50% ratio. The vertical and horizontal alveolar deficiencies were augmented by 50% mixture of ABBM with either BFPSCs (group 1) or particulated autologous bone (group 2). Titanium mesh was contoured to the desired 3D shape of the alveolar ridge and fixated to the host sites over the graft material of the two groups. At first, the amount of new bone areas was calculated by quantitative analysis of cone beam computed tomography (CBCT) images that were taken 6 months postoperatively according to regenerative techniques (group 1 vs group 2 without considering the type of bone defects). Second, these amounts were calculated in each group based on the type of defects.

RESULTS

Quantitative analysis of CBCT images revealed the areas of new bone formation were 169.5 ± 5.90 mm² and 166.75 ± 10.05 mm² in groups 1 and 2, respectively. The area of new bone formation for vertical defects were 164.91 ± 3.74 mm² and 169.36 ± 12.09 mm² in groups 1 and 2, respectively. The area of new bone formation for horizontal deficiencies were 170.51 ± 4.54 mm² and 166.98 ± 9.36 mm² in groups 1 and 2, respectively. There were no statistically significant differences between the two groups in any of the pair-wise comparisons (P > 0.05).

CONCLUSIONS

The findings of the present study demonstrated lack of difference in bone volume formation between BFPSCs and autologous particulate bone in combination with ABBM. If confirmed by future large-scale clinical trial, BFPSCs may provide an alternative to autogenous bone for reconstruction of alveolar ridge defects.

Buccal Fat Pad-Derived Stem Cells in Three-Dimensional Rehabilitation of Large Alveolar Defects: A Report of Two Cases

This case report seeks to describe efficient clinical application of adipose-derived stem cells (AdSCs) originated from buccal fat pad (BFP) in combination with conventional guided bone regeneration as protected healing space for reconstruction of large alveolar defects after extraction of multiple impacted teeth. The first case was a 19-year-old woman with several impacted teeth in the maxillary and mandibular regions, which could not be forced to erupt and were recommended for surgical extraction by the orthodontist. After this procedure, a large bone defect was created, and this space was filled by AdSC loaded natural bovine bone mineral (NBBM), which was protected with lateral ramus cortical plates, microscrews, and collagen membrane. After 6 months of post-guided bone regeneration, the patient received 6 and 7 implant placements, respectively, in the maxilla and mandible. At 10 months postoperatively, radiographic evaluation revealed thorough survival of implants. The second case was a 22-year-old man with the same complaint and large bony defects created after his teeth were extracted. After 6 months of post-guided bone regeneration, he received 4 dental implants in his maxilla and 7 implants in the mandible. At 48 months postoperatively, radiographs showed complete survival of implants. This approach represented a considerable amount of 3-dimensional bone formation in both cases, which enabled us to use dental implant therapy for rehabilitation of the whole dentition. The application of AdSCs isolated from BFP in combination with NBBM can be considered an efficient treatment for bone regeneration in large alveolar bone defects.

Impact of Tissue Harvesting Sites on the Cellular Behaviors of Adipose-Derived Stem Cells: Implication for Bone Tissue Engineering

The advantages of adipose-derived stem cells (AdSCs) over bone marrow stem cells (BMSCs), such as being available as a medical waste and less discomfort during harvest, have made them a good alternative instead of BMSCs in tissue engineering. AdSCs from buccal fat pad (BFP), as an easily harvestable and accessible source, have gained interest to be used for bone regeneration in the maxillofacial region. Due to scarcity of data regarding comparative analysis of isolated AdSCs from different parts of the body, we aimed to quantitatively compare the proliferation and osteogenic capabilities of AdSCs from different harvesting sites. In this study, AdSCs were isolated from BFP (BFPdSCs), abdomen (abdomen-derived mesenchymal stem cells (AbdSCs)), and hip (hip-derived mesenchymal stem cells (HdSCs)) from one individual and were compared for surface marker expression, morphology, growth rate, and osteogenic differentiation capability. Among them, BFPdSCs demonstrated the highest proliferation rate with the shortest doubling time and also expressed vascular endothelial markers including CD34 and CD146. Moreover, the expression of osteogenic markers were significantly higher in BFPdSCs. The results of this study suggested that BFPdSCs as an encouraging source of mesenchymal stem cells are to be used for bone tissue engineering.

Lateral Ramus Cortical Bone Plate in Alveolar Cleft Osteoplasty with Concomitant Use of Buccal Fat Pad Derived Cells and Autogenous Bone: Phase I Clinical Trial

Tissue regeneration has become a promising treatment for craniomaxillofacial bone defects such as alveolar clefts. This study sought to assess the efficacy of lateral ramus cortical plate with buccal fat pad derived mesenchymal stem cells (BFSCs) in treatment of human alveolar cleft defects. Ten patients with unilateral anterior maxillary cleft met the inclusion criteria and were assigned to three treatment groups. First group was treated with anterior iliac crest (AIC) bone and a collagen membrane (AIC group), the second group was treated with lateral ramus cortical bone plate (LRCP) with BFSCs mounted on a natural bovine bone mineral (LRCP+BFSC), and the third group was treated with AIC bone, BFSCs cultured on natural bovine bone mineral, and a collagen membrane (AIC+BFSC). The amount of regenerated bone was measured using cone beam computed tomography 6 months postoperatively. AIC group showed the least amount of new bone formation (70 ± 10.40%). LRCP+BFSC group demonstrated defect closure and higher amounts of new bone formation (75 ± 3.5%) but less than AIC+BFSC (82.5 ± 6.45%), suggesting that use of BFSCs within LRCP cage and AIC may enhance bone regeneration in alveolar cleft bone defects; however, the differences were not statistically significant. This clinical trial was registered at clinicaltrial.gov with NCT02859025 identifier.

Buccal Fat Pad as a Potential Source of Stem Cells for Bone Regeneration: A Literature Review

Adipose tissues hold great promise in bone tissue engineering since they are available in large quantities as a waste material. The buccal fat pad (BFP) is a specialized adipose tissue that is easy to harvest and contains a rich blood supply, and its harvesting causes low complications for patients. This review focuses on the characteristics and osteogenic capability of stem cells derived from BFP as a valuable cell source for bone tissue engineering. An electronic search was performed on all in vitro and in vivo studies that used stem cells from BFP for the purpose of bone tissue engineering from 2010 until 2016. This review was organized according to the PRISMA statement. Adipose-derived stem cells derived from BFP (BFPSCs) were compared with adipose tissues from other parts of the body (AdSCs). Moreover, the osteogenic capability of dedifferentiated fat cells (DFAT) derived from BFP (BFP-DFAT) has been reported in comparison with BFPSCs. BFP is an easily accessible source of stem cells that can be obtained via the oral cavity without injury to the external body surface. Comparing BFPSCs with AdSCs indicated similar cell yield, morphology, and multilineage differentiation. However, BFPSCs proliferate faster and are more prone to producing colonies than AdSCs.

Induced pluripotent stem cells as a new getaway for bone tissue engineering: A systematic review

OBJECTIVES

Mesenchymal stem cells (MSCs) are frequently used for bone regeneration, however, they are limited in quantity. Moreover, their proliferation and differentiation capabilities reduce during cell culture expansion. Potential application of induced pluripotent stem cells (iPSCs) has been reported as a promising alternative source for bone regeneration. This study aimed to systematically review the available literature on osteogenic potential of iPSCs and to discuss methods applied to enhance their osteogenic potential.

METHODS AND MATERIALS

A thorough search of MEDLINE database was performed from January 2006 to September 2016, limited to English-language articles. All in vitro and in vivo studies on application of iPSCs in bone regeneration were included.

RESULTS

The current review is organized according to the PRISMA statement. Studies were categorized according to three different approaches used for osteo-induction of iPSCs. Data are summarized and reported according to the following variables: types of study, cell sources used for iPSC generation, applied reprogramming methods, applied osteo-induction methods and treatment groups.

CONCLUSION

According to the articles reviewed, osteo-induced iPSCs revealed osteogenic capability equal to or superior than MSCs; cell sources do not significantly affect osteogenic potential of iPSCs; addition of resveratrol to the osteogenic medium (OM) and irradiatiation after osteogenic induction reduce teratoma formation in animal models; transfection with lentiviral bone morphogenetic protein 2 results in higher mineralization compared to osteo-induction in OM; addition of TGF-β, IGF-1 and FGF-β to OM increases osteogenic capability of iPSCs.

Fabrication of a three-dimensional β-tricalcium-phosphate/gelatin containing chitosan-based nanoparticles for sustained release of bone morphogenetic protein-2: Implication for bone tissue engineering

Fabrication of an ideal scaffold having proper composition, physical structure and able to have sustained release of growth factors still is challenging for bone tissue engineering. Current study aimed to design an appropriate three-dimensional (3-D) scaffold with suitable physical characteristics, including proper compressive strength, degradation rate, porosity, and able to sustained release of bone morphogenetic protein-2 (BMP2), for bone tissue engineering. A highly porous 3-D β-tricalcium phosphate (β-TCP) scaffolds, inside of which two perpendicular canals were created, was fabricated using foam-casting technique. Then, scaffolds were coated with gelatin layer. Next, BMP2-loaded chitosan (CS) nanoparticles were dispersed into collagen hydrogel and filled into the scaffold canals. Physical characteristics of fabricated constructs were evaluated. Moreover, the capability of given construct for bone regeneration has been evaluated in vitro in interaction with human buccal fat pad-derived stem cells (hBFPSCs). The results showed that gelatin-coated TCP scaffold with rhBMP2 delivery system not only could act as a mechanically and biologically compatible framework, but also act as an osteoinductive graft by sustained delivering of rhBMP2 in a therapeutic window for differentiation of hBFPSCs towards the osteoblast lineage. The proposed scaffold model can be suggested for delivering of cells and other growth factors such as vascular endothelial growth factor (VEGF), alone or in combination, for future investigations.

Adipose Tissue and Mesenchymal Stem Cells: State of the Art and Lipogems® Technology Development

In the past few years, interest in adipose tissue as an ideal source of mesenchymal stem cells (MSCs) has increased. These cells are multipotent and may differentiate in vitro into several cellular lineages, such as adipocytes, chondrocytes, osteoblasts, and myoblasts. In addition, they secrete many bioactive molecules and thus are considered “mini-drugstores.” MSCs are being used increasingly for many clinical applications, such as orthopedic, plastic, and reconstructive surgery. Adipose-derived MSCs are routinely obtained enzymatically from fat lipoaspirate as SVF and/or may undergo prolonged ex vivo expansion, with significant senescence and a decrease in multipotency, leading to unsatisfactory clinical results. Moreover, these techniques are hampered by complex regulatory issues. Therefore, an innovative technique (Lipogems®; Lipogems International SpA, Milan, Italy) was developed to obtain microfragmented adipose tissue with an intact stromal vascular niche and MSCs with a high regenerative capacity. The Lipogems® technology, patented in 2010 and clinically available since 2013, is an easy-to-use system designed to harvest, process, and inject refined fat tissue and is characterized by optimal handling ability and a great regenerative potential based on adipose-derived MSCs. In this novel technology, the adipose tissue is washed, emulsified, and rinsed and adipose cluster dimensions gradually are reduced to about 0.3 to 0.8 mm. In the resulting Lipogems® product, pericytes are retained within an intact stromal vascular niche and are ready to interact with the recipient tissue after transplantation, thereby becoming MSCs and starting the regenerative process. Lipogems® has been used in more than 7000 patients worldwide in aesthetic medicine and surgery, as well as in orthopedic and general surgery, with remarkable and promising results and seemingly no drawbacks. Now, several clinical trials are under way to support the initial encouraging outcomes. Lipogems® technology is emerging as a valid intraoperative system to obtain an optimal final product that may be used immediately for regenerative purposes.