Oral and Maxillofacial Autologous Fat Transplantation: History, Clinical Application Status and Research Progress

Dual Network Hydrogels Based on PRP and SA Promote the Retention Rate and Vascularization of Transplanted Fat

BACKGROUND

Autologous adipose tissue often experiences ischemia and hypoxia after transplantation, leading to low retention rates and unstable operative impacts due to necrotic absorption. Platelet-rich plasma (PRP) can enhance fat regeneration and increase the fat retention rate after transplantation. However, the quick release of growth factors (GFs) in PRP decreases therapeutic efficiency. This study aimed to achieve a slow release of PRP to promote fat retention.

METHODS

We prepared a dual-network hydrogel (DN gel) based on FDA-approved PRP and sodium alginate (SA) through a simple "one-step" activation process. In vivo study, adipose tissue with saline (control group), SA gel (SA gel group), PRP gel (PRP gel group), and DN gel (DN gel group) was injected subcutaneously into the dorsum of nude mice. At 4 and 12 weeks after injection, tissues were assessed for volume and weight. Hematoxylin and eosin staining (HE) and immunofluorescence staining were performed for histological assessment.

RESULTS

DN gel exhibits long-lasting growth factor effects, surpassing conventional clinical PRP gel regarding vascularization potential. In fat transplantation experiments, DN gel demonstrated improved vascularization of transplanted fat and increased retention rates, showing promise for clinical applications.

CONCLUSIONS

DN gel-assisted lipofilling can significantly improve the retention rate and quality of transplanted fat. DN gel-assisted lipofilling, which is considered convenient, is a promising technique to improve neovascularization and fat survival.

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Pluronic F-127 Hydrogel Loaded with Human Adipose-Derived Stem Cell-Derived Exosomes Improve Fat Graft Survival via HIF-1α-Mediated Enhancement of Angiogenesis

Purpose

Autologous fat grafting is playing an increasingly important role in plastic surgery. However, high absorption and low survival of autologous fat grafts limit their clinical application. This study aimed to investigate whether human adipose-derived stem cell-derived exosomes (hASC-Exos) encapsulated in a PF-127 hydrogel can improve the survival of autologous fat grafts and to elucidate the underlying mechanisms.

Patients and Methods

Exosomes were isolated from hASCs and identified using transmission electron microscopy, nanoparticle tracking analysis and Western blotting. We performed functional assays in vitro to assess the effect of hASC-Exos on proliferation, migration, and tube formation as well as their regulatory role in the HIF-1α/VEGF signaling pathway. hASC-Exos encapsulated in the PF-127 hydrogel were used as an in vivo autologous fat graft model. The effects of the PF-127 hydrogel/hASC-Exos and the role of the HIF-1α/VEGF signaling pathway in promoting angiogenesis in an autologous fat grafting model were assessed.

Results

hASC-Exos were taken up by human umbilical vein endothelial cells and enhanced their proliferation, migration, and tubule formation in vitro. The effects of hASC-Exos on promoting angiogenesis were mediated by the HIF-1α/VEGF signaling pathway. Moreover, we fabricated a PF-127 hydrogel for the sustained release of hASC-Exos, and in vivo results showed that hASC-Exos encapsulated in PF-127 hydrogel improved the survival of autologous fat grafts.

Conclusion

Our findings indicated that hASC-Exos encapsulated in PF-127 hydrogel serve as a key regulator of angiogenesis by activating the HIF-1α/VEGF signaling pathway and provide a promising strategy for autologous fat grafting treatment.

Clinical application of 3D-printed PEEK implants for repairing mandibular defects

The aim of this study was to investigate and discuss the efficacy of 3D-printed PEEK implants in personalized reconstruction of mandibular segmental defects. This study was a single-center case series. Six patients who underwent mandibular reconstruction with a custom-made 3D-printed PEEK implant were enrolled. Patient demographics, photographs, computed tomography (CT), and other clinical data were collected and analyzed pre- and postoperatively. The average patient age was 60.0 ± 15.09 years. The mean operative time was 213.33 ± 30.77 min, and the postoperative follow-up time ranged from 10 to 24 months. Mandibular segmental defects ranged from the symphysis to the condyle. Five patients did not have any postoperative complications and were satisfied with the cosmetic and functional results. One patient had to undergo removal of the PEEK implant because of implant exposure at 10 months after surgery. PEEK implants can repair different forms of defect in the mandible, maintaining the original shape of the mandible, whilst not affecting mandible functions, such as mastication and temporomandibular joint movement. However, PEEK implantation requires the strict selection of appropriate indications, especially with regard to the evaluation of soft-tissue conditions in the implanted area.

The Application and Efficacy Evaluation of Autologous Fat Transplantation in Antiaging of the Face: Systematic Review and Meta-Analysis

Objective

To evaluate the therapy of autologous fat fine-grain transplantation in the application of antiaging facial by metaelaboration method.

Methods

In Chinese and English databases, such as Wanfang, Weipu, CNKI, PubMed, Cochrane Library, and EMBASE, the literature on the use of autologous fat fines graft in antiaging facial was collected, covering randomized comparative trials, nonrandomized comparative studies, comparative case studies, cohort studies, case reports, and so forth. Meta-analyses were also conducted on complication rates, beauty seeker satisfaction, and one-shot success rates.

Results

This study included 23 studies that held metaelaborations, including a total of 2852 beauty seekers. According to metaelaboration, the complication rate was 0.02 (95% CI: 0.01, 0.04), the satisfaction rate of beauty seekers was 0.95 (95% CI: 0.91, 0.97), and the success rate of one injection is 0.79 (95% CI: 0.73, 0.84).

Conclusion

Autologous fat fine-grain transplantation is obvious and stable in the use of antiaging facial, and it is necessary to popularize the use in clinical practice.

Inhibition of RIP3 increased ADSC viability under OGD and modified the competency of adipogenesis, angiogenesis, and inflammation regulation

Adipose-derived stem cells (ADSCs) showed decreased cell viability and increased cell death under oxygen-glucose deprivation (OGD). Meanwhile, vital necroptotic proteins, including receptor-interacting protein kinase (RIP) 3 (RIP3) and mixed lineage kinase domain-like pseudokinase (MLKL), were expressed in the early stage. The present study aims to explore the effect of necroptosis inhibition on ADSCs. ADSCs were obtained from normal human subcutaneous fat and verified by multidirectional differentiation and flow cytometry. By applying cell counting kit-8 (CCK-8), calcein/propidium iodide (PI) staining and immunostaining, we determined the OGD treatment time of 4 h, a timepoint when the cells showed a significant decrease in viability and increased protein expression of RIP3, phosphorylated RIP3 (pRIP3) and phosphorylated MLKL (pMLKL). After pretreatment with the inhibitor of RIP3, necroptotic protein expression decreased under OGD conditions, and cell necrosis decreased. Transwell assays proved that cell migration ability was retained. Furthermore, the expression of the adipogenic transcription factor peroxisome proliferator-activated receptor γ (PPARγ) and quantitative analysis of Oil Red O staining increased in the inhibitor group. The expression of vascular endothelial growth factor-A (VEGFA) and fibroblast growth factor 2 (FGF2) and the migration test suggest that OGD increases the secretion of vascular factors, promotes the migration of human umbilical vein endothelial cells (HUVECs), and forms unstable neovascularization. ELISA revealed that inhibition of RIP3 increased the secretion of the anti-inflammatory factor, interleukin (IL)-10 (IL-10) and reduced the expression of the proinflammatory factor IL-1β. Inhibition of RIP3 can reduce the death of ADSCs, retain their migration ability and adipogenic differentiation potential, reduce unstable neovascularization and inhibit the inflammatory response.