The effects of the centrifugation speed on the survival of autogenous fat grafts in a rat model

Evaluation of the Regenerative Capacity of Demineralized Bone Matrix vs Fat Graft in Alveolar Cleft Model in Albino Rats

AIM

This study was performed to evaluate the regenerative capacity of demineralized bone matrix vs fat graft, both guided by pericardium membrane in alveolar cleft model in albino rats.

MATERIALS AND METHODS

A total of 72 rats were required in this study. A surgical bone defect with a 7 mm length × 4 mm width × 3 mm depth was created as a model of an alveolar cleft, then the rats were divided randomly into four equal groups each group contained 18 rats: control group (defect only), the membrane group (the defect was covered by the pericardium membrane), the demineralized bone matrix (DBM) group (the defect was filled with DBM guided by pericardium membrane) and fat group (the defect was filled with a fat graft guided by the pericardium membrane). Around 6 rats from each group were euthanized after 2, 4, and 8 weeks. Skulls were scanned with cone beam computed tomography (CBCT) and harvested for histological evaluation with routine H&E immunohistochemical stains (Anti-osteocalcin and Anti-Wnt5a). The data was recorded and statistically analyzed by a two-way ANOVA.

RESULTS

The study showed a notable formation of new bone, and expression of OCN and Wnt5a were notably increased by time in the fat group. However, the density of bone grafts and OCN and Wnt5a expression decreased with time in the DBM group. Control and membrane groups showed negative OCN and Wnt5a immune-reactivity in the cleft site.

CONCLUSION

Fat graft results were superior to DBM results with regard to mucosal closure and accelerated bone regeneration, and may represent an effective treatment for alveolar cleft reconstruction.

CLINICAL SIGNIFICANCE

Finding an inexpensive, accessible, biocompatible and easily manipulated treatment for craniofacial reconstruction and fat graft fulfilled the desired aims. Further investigations with prolonged evaluation periods are needed. How to cite this article: Abdel Raouf E, Elsherbini AM, Abdel Salam Yousef Y, et al. Evaluation of the Regenerative Capacity of Demineralized Bone Matrix vs Fat Graft in Alveolar Cleft Model in Albino Rats. J Contemp Dent Pract 2024;25(6):554-562.

Comparative Analysis of a New Automatic System and Four Existing Techniques for Autologous Fat Grafting

Background

Autologous fat grafting is increasingly used worldwide and is a very attractive technique in many ways. However, treatment duration and postinjection tissue resorption remain problematic elements, which are largely related to the preparation method used. Moreover, few scientific studies objectively compare different fat preparation methods. This study analyzes the efficiency and quality of lipoaspirates prepared with a new filtration/centrifugation system (Adipure) in comparison with several existing techniques.

Methods

Patient lipoaspirates were processed by five different techniques: decantation, centrifugation, Macrofill, Puregraft, and Adipure. Adipose tissue was evaluated in vitro for tissue resorption and oil formation, as well as in vivo after subcutaneous injections in immunodeficient mice. Adipose grafts were collected after 1 month, weighed, and analyzed by histology with a detailed scoring method.

Results

Decanting gives inferior results to all other techniques, in terms of amount of tissue and oil in vitro, or graft weight and histological analysis in vivo. Methods using classical Coleman centrifugation (1200g), or a modified one (400g) associated with washes (Macrofill) produce very similar results, both in vitro and in vivo. Techniques using filtration systems (Puregraft and Adipure) produce less oil overall and have a higher grafting efficiency. The best results regarding grafting efficiency and oil quantity are found with the Adipure device.

Conclusions

A combination of filtration and very low-speed centrifugation potentiates the advantages of these techniques, in terms of graft efficiency. The adipose tissue purification being done in a few minutes, in an automatic way, undoubtedly provides a strong advantage for the use of this new system.

Assessment of the Causes of Differences in Centrifugation Protocols as a Fat-Processing Technique: A Systematic Literature Review

BACKGROUND

Centrifugation has been widely used for fat graft processing. However, numerous different centrifugation protocols have been proposed in different studies. Investigation of these major differences is needed to clarify ambiguities and to achieve standardization. This review aimed to assess the causes of differences in centrifugation protocols as a fat-processing technique.

METHODS

Full-text and English-language articles between 1990 and 2020 were included in this study. Articles that assess the effect of centrifugation on fat graft survival with the following research purposes were selected: determination of the effect of centrifugation force/speed, determination of the effect of centrifugation time/duration, and comparison with other fat-processing techniques.

RESULTS

Fifty-four full-text, English-language articles were included. The number of articles that assessed centrifugation force/speed was 17 and centrifugation duration/time was 4, and the number of articles that compared centrifugation with other fat-processing techniques was 29 and centrifugation with noncentrifugation techniques was 4. Based on the study design, 25 experiments were performed in vivo, and 41 were performed in vitro.

CONCLUSION

Misuse of force (g) and speed (rpm) for defining the centrifugation protocol, differences in selected techniques for the graft harvest and graft transfer steps and differences in the analysis methods for fat graft survival are the main causes of these substantial variations among studies.

LEVEL OF EVIDENCE III

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.

Supportive Use of Adipose-Derived Stem Cells in Cell-Assisted Lipotransfer for Localized Scleroderma

BACKGROUND

The authors aimed to analyze factors related to lipotransfer for localized scleroderma, and to explore the feasibility of cell-assisted lipotransfer for localized scleroderma treatment.

METHODS

Abdominal fat samples were taken from six scleroderma patients without corticosteroid therapy, five scleroderma patients with corticosteroid therapy, and 10 normal liposuction patients. Their quantity, morphology, and proliferation ability were measured. Blood flow was measured by laser speckle contrast imaging in localized scleroderma lesions and normal contralateral regions for eight localized scleroderma patients. Bleomycin-induced skin fibrosis nude mice were also used to investigate differences between lipotransfer and cell-assisted lipotransfer. Fat weight was measured, and expression of transforming growth factor (TGF)-β1 and type III collagen in the injected skin was determined by immunohistochemistry.

RESULTS

The number of stem cells from scleroderma patients with corticosteroid treatment was significantly reduced. Mean blood perfusion in localized scleroderma lesions was not significantly different than in the contralateral normal regions. In normal nude mice, there were no significant changes in TGF-β1 and type III collagen between the control, lipotransfer, and cell-assisted lipotransfer groups, whereas in bleomycin-induced skin fibrosis nude mice, lipotransfer and cell-assisted lipotransfer reduced TGF-β1 and type III collagen expression.

CONCLUSIONS

For scleroderma patients, fewer adipose-derived stem cells, because of a history of corticosteroid therapy and a local inflammatory microenvironment, are more important factors, whereas blood supply showed no significant change. Therefore, cell-assisted lipotransfer not only improves the survival rate of transplanted fat but also improves skin texture in bleomycin-induced skin fibrosis nude mice.

Preliminary results with non-centrifuged autologous fat graft and percutaneous aponeurotomy for treating Dupuytren's disease

The aim of this study was to describe our experience with treating Dupuytren's disease using needle aponeurotomy and non-centrifuged autologous fat grafting. The study included 17 patients (18 hands). Patients were treated with needle aponeurotomy and non-centrifuged autologous fat graft under general anesthesia. The fat grafts were injected into the surgical area so as to stay in contact with the operated site. An extension splint was used for 1 week postoperatively and the patients received hand therapy for 3 weeks. Before the treatment, the contracture in the proximal interphalangeal and metacarpophalangeal joints was a mean of 45.06 ± 13.44 degrees and 36.56 ± 13.09 degrees, respectively. It was 1.61 ± 1.65 and -0.56 ± 3.78 degrees at 3 months, respectively. The difference between these measurements was statistically significant. The mean follow-up period was 12 months. The results were satisfactory and no complications were observed during the follow-up period. Based on the results of the study, percutaneous aponeurotomy with non-centrifuged autologous fat grafting was found to have significantly beneficial effects in the treatment of Dupuytren's disease.