Bioactive decellularized adipose matrix prepared using a rapid, nonchemical/enzymatic method for adipogenesis.

Recent developments in the field of regenerative surgeries and medical applications have led to a renewed interest in adipose tissue-enriched mesenchymal stem cell scaffolds. Various advantages declared for the decellularized adipose matrix (DAM) have caused its extensive use in the transfer of stem cells or growth factors for soft tissue regeneration induction. Meanwhile, the long-term application of detergents toward DAM regeneration has been assumed as a risky obstacle in this era. Herein, a rapid, mechanical protocol was developed to prepare DAM (M-DAM) without chemicals/enzymes and was comprehensively compared with the ordinary DAM (traditional chemical method). Accordingly, this method could effectively hinder oils and cells, sustain the structural and biological elements, and contain a superior level of collagen content. In addition, more protein numbers, as well as higher basement membrane elements, glycoproteins, and extracellular matrix-related proteins were detected in the regenerated M-DAM. Also, superior adipogenesis and angiogenesis proteins were distinguished. The noncytotoxicity of the M-DAM was also approved, and a natural ecological niche was observed for the proliferation and differentiation of stem cells, confirming its great potential for vascularization and adipogenesis in vivo. The suggested technique could effectively prepare the modified DAM in variant constructions of tablets, powders, emulsions, hydrogels, and different three-dimensional-printed structures. Hence, this rapid, mechanical process can produce bioactive DAM, which has the potential to be widely used in various research fields of regenerative medicine.

Meta-Analysis of the Oncological Safety of Autologous Fat Grafting After Breast Cancer on Basic Science and Clinical Studies.

BACKGROUND: The purpose of the present study was to comprehensively evaluate the oncological safety of autologous fat grafting after breast cancer by combining experimental and clinical studies. METHODS: All studies published before August 2021 were collected by searching PubMed, Cochrane, Embase, Web of Science, SINOMED, and China National Knowledge Infrastructure. After screening the research and extracting the data, RevMan was used to perform the meta-analysis. RESULTS: Five basic science studies and 26 clinical studies, involving a total of 10,125 patients, were eventually included. In the basic science studies, adipose-derived stem cells promoted breast cancer growth, but fat grafting and adipose-derived stem cells plus fat grafting were not associated with breast cancer growth. An overall analysis of clinical studies showed that autologous fat grafting does not increase the risk of breast cancer recurrence. Subgroup analyses indicated that autologous fat grafting did not increase the risk of breast cancer recurrence in Asian or Caucasian patients, in patients undergoing breast-conserving surgery or modified radical mastectomy, in patients with in situ carcinomas or invasive carcinomas, or in patients undergoing postoperative radiotherapy. CONCLUSION: This study combined experimental and clinical studies to conclude that autologous fat grafting does not increase the risk of breast cancer recurrence. However, the experimental results suggest that adipose-derived stem cells should be used with caution after breast cancer surgery. 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 .

Bone marrow mesenchymal stem cells enhance angiogenesis and promote fat retention in fat grafting via polarized macrophages.

BACKGROUND: Fat grafting is one of the most common soft tissue filling methods in plastic surgery. Bone marrow mesenchymal stem cell (BM-MSC) transplantation is an effective method for improving graft retention. However, the role of BM-MSCs in fat transplantation is not completely clear. METHODS: Human fat particles, together with BM-MSCs or PBS as a control, were subcutaneously transplanted into the backs of nude mice. Samples were taken on days 14, 30 and 90 post-grafting to calculate the fat graft retention rate, and tissue staining was evaluated. Furthermore, macrophages were treated with BM-MSC conditioned medium (BM-MSC-CM) to identify the beneficial component secreted by these stem cells. RESULTS: In this study, we found that BM-MSCs improved retention by enhancing angiogenesis in fat grafting. Further analysis revealed that BM-MSCs could significantly inhibit the expression of the proinflammatory M1 macrophage markers interleukin (IL)-1ß, tumor necrosis factor-α (TNF-α) and IL-6 in the early stages of fat grafting and promote the expression of the anti-inflammatory M2 macrophage markers Arg1, IL-10 and VEGF. Furthermore, our results showed that IL-10 secreted by BM-MSCs induced M2 macrophage polarization in vitro. CONCLUSIONS: BM-MSC transplantation can improve the fat retention rate and promote angiogenesis, which may be related to M2 macrophages. These results help elucidate the role of BM-MSCs in fat grafting.

Severe Vascular Complications Caused by Facial Autologous Fat Grafting: A Critical Review.

BACKGROUND: Vascular embolism is the most severe complication after autologous fat grafting. With a worldwide increase in fat grafting, there has been a rise in severe vascular complications, such as ophthalmic artery embolism, cerebral artery embolism, and even death. This article aims to review the role of fat in causing severe vascular complications and the association between fat grafting and severe vascular complications. METHODS: A critical review was conducted by appraising the cases of severe vascular complications associated with facial fat grafting reported globally. Repeated cases that were reported in multiple publications were further screened. RESULTS: The final search yielded 50 publications in English that met the inclusion criteria for review. A total of 113 cases of fat-induced severe vascular complications in the literature were identified. The number of cases reported yearly has increased over time, with even more significant increases since 2010. The glabella and temple are the most common sites of severe vascular complications described in the literature. In addition, only one case of ophthalmic artery embolism and one case of cerebral artery embolism have been treated successfully. CONCLUSIONS: Given the increase in reported cases of severe vascular complications, both doctors and patients should pay careful attention to the risks of facial fat grafting. Because of the unclear mechanism of vascular embolism and the lack of guidelines for prevention and treatment, the effective cure rate is unsatisfactory. We propose that preventing vascular embolism is a priority in fat grafting and that timely, multidisciplinary treatment should be performed when severe vascular complications occur. It is necessary in future studies to explore the mechanisms of vascular embolism and effective treatment strategies to promote the development of fat grafting.

Use of the Inferior Whorl for Detecting Age-Related Changes in Human Corneal Subbasal Nerve Plexus with Laser Scanning Confocal Microscopy.

PURPOSE: The purpose of this study was to determine the effect of aging on the corneal subbasal nerve plexus (SNP) by employing a wide-field mapping technique of composite images, scanned at the location of a distinctive spiraled subbasal nerve pattern located 1-2 mm inferior to the corneal apex (the inferior whorl) for SNP structural quantification. MATERIALS AND METHODS: Central corneal tactile sensitivity (CCTS) and inferior whorl length (IWL) were compared among individuals in 3 age-groups (20-39 years, 40-59 years, and 60-79 years). Statistical analyses constituted the Kruskal-Wallis test, one-way analysis of variance (with the post hoc least significant difference test), Spearman correlation coefficient, and linear regression analysis. RESULTS: CCTS remained stable until the age of 50 years, when it began to decrease; the mean CCTS was 58.15 ± 2.46 mm in the group aged 20-39 years, 55.74 ± 3.85 mm in the group aged 40-59 years, and 50.23 ± 3.27 mm in the group aged 60-79 years. IWL decreased with increasing age, with a corresponding linear decline of 0.2088 mm/mm2 per year, and the mean IWL was 25.43 ± 4.50 mm/mm2 in the group aged 20-39 years, 22.71 ± 6.19 mm/mm2 in the group aged 40-59 years, and 18.60 ± 4.21 mm/mm2 in the group aged 60-79 years. CONCLUSION: Our work provided a more accurate and repeatable method for corneal nerve analysis using laser scanning confocal microscopy. By using this technique, we confirmed that aging is associated with progressive reduction in subbasal nerve length.

New Insights Into the Skin Microbial Communities and Skin Aging.

Although it is well-known that human skin aging is accompanied by an alteration in the skin microbiota, we know little about how the composition of these changes during the course of aging and the effects of age-related skin microbes on aging. Using 16S ribosomal DNA and internal transcribed spacer ribosomal DNA sequencing to profile the microbiomes of 160 skin samples from two anatomical sites, the cheek and the abdomen, on 80 individuals of varying ages, we developed age-related microbiota profiles for both intrinsic skin aging and photoaging to provide an improved understanding of the age-dependent variation in skin microbial composition. According to the landscape, the microbial composition in the Children group was significantly different from that in the other age groups. Further correlation analysis with clinical parameters and functional prediction in each group revealed that high enrichment of nine microbial communities (i.e., Cyanobacteria, Staphylococcus, Cutibacterium, Lactobacillus, Corynebacterium, Streptococcus, Neisseria, Candida, and Malassezia) and 18 pathways (such as biosynthesis of antibiotics) potentially affected skin aging, implying that skin microbiomes may perform key functions in skin aging by regulating the immune response, resistance to ultraviolet light, and biosynthesis and metabolism of age-related substances. Our work re-establishes that skin microbiomes play an important regulatory role in the aging process and opens a new approach for targeted microbial therapy for skin aging.

Survey report on keratoplasty in China: A 5-year review from 2014 to 2018.

To provide the general information on corneal transplantation (CT) in China, China Cornea Society designed a questionnaire on CT from 2014 to 2018 and entrusted it to 31 committee members for implementation of the survey nationwide. This article presents the results of the survey and compares the indicators used in the survey and those in the annual statistical report released by the Eye Bank Association of America (EBAA). The number of corneal transplantations completed by the 64 hospitals from 2014 to 2018 was respectively 5377, 6394, 7595, 8270 and 8980, totally 36,616 (22,959 male and 13,657 female). The five largest hospitals by the number of corneal transplantations completed 15,994 surgeries in total, accounting for 43.68% of all the surgeries performed in the 64 hospitals. The most common indication for corneal transplantations was corneal leukoma (7683, 20.98%), followed by bacterial keratitis (4209, 11.49%), corneal dystrophies (4189, 11.44%), keratoconus (3578, 9.77%) and corneal perforation (2839, 7.75%). The main surgical techniques were penetrating keratoplasty (PK) (19,896, 54.34%), anterior lamellar keratoplasty (ALK) (13,869, 37.88%). The proportion of PK decreased from 57.97% in 2014 to 52.88% in 2018 while the proportion of ALK increased from 36.04% in 2014 to 37.92% in 2018. The geographical distribution of keratoplasties performed in China is unbalanced. PK and ALK were the main techniques of CT and corneal leukoma, bacterial keratitis and corneal dystrophies were the main indications for CT in China.

Decellularized adipose matrix provides an inductive microenvironment for stem cells in tissue regeneration.

Stem cells play a key role in tissue regeneration due to their self-renewal and multidirectional differentiation, which are continuously regulated by signals from the extracellular matrix (ECM) microenvironment. Therefore, the unique biological and physical characteristics of the ECM are important determinants of stem cell behavior. Although the acellular ECM of specific tissues and organs (such as the skin, heart, cartilage, and lung) can mimic the natural microenvironment required for stem cell differentiation, the lack of donor sources restricts their development. With the rapid development of adipose tissue engineering, decellularized adipose matrix (DAM) has attracted much attention due to its wide range of sources and good regeneration capacity. Protocols for DAM preparation involve various physical, chemical, and biological methods. Different combinations of these methods may have different impacts on the structure and composition of DAM, which in turn interfere with the growth and differentiation of stem cells. This is a narrative review about DAM. We summarize the methods for decellularizing and sterilizing adipose tissue, and the impact of these methods on the biological and physical properties of DAM. In addition, we also analyze the application of different forms of DAM with or without stem cells in tissue regeneration (such as adipose tissue), repair (such as wounds, cartilage, bone, and nerves), in vitro bionic systems, clinical trials, and other disease research.

Multi-parameter reconstruction of velocity and density using ultrasonic tomography based on full waveform inversion.

In this paper, an ultrasonic tomography method based on acoustic multi-parameter full waveform inversion (FWI) is developed for high-resolution reconstructions of velocity and density in metal components. The challenging issue in multi-parameter FWI is to deal with the trade-off effects between different parameters of different natures. Moreover, different parameters have different orders of amplitudes in the wave-field which make the inversion ill-conditioned. The inverse Hessian has been shown to mitigate the coupling effects and rescale the amplitudes of different parameters, and then the reliable updates of different parameters are available. The simultaneous reconstructions of velocity and density by using the truncated Gauss-Newton method, in which the inverse Hessian can be considered through a matrix-free conjugate gradient solution of the Gauss-Newton normal equation, are investigated by simulation as well as experiment on the centred inclusions. The results show that this method can effectively alleviate the trade-off effects between velocity and density, and thus the velocity of the inclusion is accurately reconstructed and the reconstruction of the density is well achieved.

Performance Evaluation of IGRA-ELISA and T-SPOT.TB for Diagnosing Tuberculosis Infection.

BACKGROUND: To explore the application value of IGRA-ELISA in the diagnosis of tuberculosis. METHODS: A total of 68 tuberculosis and 58 other pulmonary disease case samples were obtained. All the samples were tested by IGRA-ELISA and T-SPOT.TB assay in parallel. The consistency of IGRA-ELISA and T-SPOT.TB in the diagnosis of TB was analyzed. Five different methods for the diagnosis of TB were assayed: IGRA-ELISA, T-SPOT.TB, AFB staining, TB-Ab, and PPD. For the different PPD positive degrees, IGRA-ELISA and T-SPOT.TB positive rates were calculated. AFB staining positive and negative samples were analyzed by IGRA-ELISA, T-SPOT.TB, TB-Ab, and PPD. Positive rates, sensitivity, specificity, PPV, NPV and accuracy values of the five different detection methods were compared. RESULTS: There was good consistency between IGRA-ELISA and T-SPOT.TB in the diagnosis of TB and other pulmonary diseases. Compared with T-SPOT.TB, there was a significant correlation between the absorbance value of IGRA-ELISA and the number of ESAT-6 or CFP-10-specific SFCs (r = 0.902, p < 0.001; r = 0.901, p < 0.001). There was a significant difference in the positive rates among the above five different detection methods in the TB group and non-TB group (p < 0.001). For the different PPD positive degrees, there were highly significant differences in the positive rates of IGRA-ELISA and T-SPOT.TB in non-TB group; no similar trend was observed in the TB group. No significant differences in sensitivity, specificity, PPV, NPV, accuracy, LR+ and LR- were observed between IGRA-ELISA and T-SPOT.TB. The positive rates of IGRA-ELISA and T-SPOT.TB in the TB group were significantly higher than that of AFB staining, TB-Ab, and PPD (p < 0.05). IGRA-ELISA and T-SPOT.TB combined with AFB staining could further improve the sensitivity of tuberculosis detection without reducing its specificity. The AUC of IGRA-ELISA, ESAT-6, CFP-10, and T-SPOT.TB were 0.923, 0.893, 0.937, and 0.919, respectively. CONCLUSIONS: There was good correlation and consistency between the IGRA-ELISA and T-SPOT.TB in the diagnosis of TB. The sensitivity and accuracy of IGRA-ELISA were significantly better than those of AFB staining, TB-Ab, and PPD. IGRA-ELISA combined with AFB staining could further improve the diagnosis of tuberculosis.

Impact of perioperative blood transfusion on gene expression biomarkers in patients with gastrointestinal cancer.

OBJECTIVES: To explore the impacts of perioperative blood transfusion on specific pattern of inflammatory gene expression and nosocomial infections in gastrointestinal cancer patients. METHODS: A total of 60 gastrointestinal cancer patients aged over 27 years were recruited, blood transfusion was administered to 30 patients. The peripheral venous blood was drawn from the 30 patients undergoing transfusions and messenger RNA (mRNA) was extracted from PAXGene tubes collected before surgery and at 48 h following the operation. T-helper cell subtype transcription factors were quantified using quantitative real-time polymerase chain reaction. These genes were selected based on their ability to represent specific immune pathways and their expression level of Th1, Th2 and Th17 and the major Treg-specific TFs T-bet, GATA-3, RORγt and FOXP3 were measured. Postoperative infections were documented using predefined criteria. RESULTS: There were significantly lower in Th1-specific TF T-bet (P < 0.001) mRNA levels and significantly higher in Th2-specifc TF, GATA-3 (P < 0.001) mRNA levels assayed at 48 h. There was significantly lower in T-bet mRNA/GATA-3 (P < 0.001) mRNA ratio assayed at 48 h. There were significantly higher in Th17-specific TF RORγt (P < 0.001) and Treg-specific TF Foxp3 (P < 0.001) mRNA levels assayed at 48 h. Patients receiving a blood transfusion were more likely to develop postoperative infections (P = 0.02). CONCLUSION: There is an association between an immunosuppressive pattern of gene expressions and blood transfusion. This gene expression profile includes a reduction in the activity of T helper cell type 1 (Th1) pathways in those patients receiving a blood transfusion. Furthermore, blood transfusion was associated with an increased susceptibility to nosocomial infections.

[Targeting VEGF siRNA transfection by new polymeric liposomes to inhibit retinal neovascularization].

OBJECTIVE: To formulate and evaluate polymeric liposomes (PL) nanoparticles as a novel non-viral gene delivery. To explore its applicability and feasibility as a non-viral vector for gene transportation. METHOD: Experimental study. To construct the orongoxygen induced retinopathy (OIR) mouse (C57BL/6J) model on the basis of improved Smith's methods. Western blot was used to measure VEGF protein expression in retinal tissue at P17 and P22. HE staining and fluorescein-dextran angiography of retinal vascular were performed to observe the morphologic alterations of retinal neovascularization. Frozen-section was used to show the membrane translocation of PL. RESULTS: In fluorescence angiograms, irregular neovascularization and fluoresce leakage were observed in OIR model. The results of Western blot showed that VEGF protein in retinal tissues were significantly different among groups (F = 158.207, P = 0.000) at P17 and P22 (F = 25.695, P = 0.000). The protein level was lower in both PL (0.70 ± 0.03) and Lipo group (0.66 ± 0.04) at P17 (P = 0.092), and the lower level was presented at P22 in PL group (0.50 ± 0.03) than in Lipo group (0.53 ± 0.05) (P < 0.05). HE staining were performed to observe the significantly improvements of retinal neovascularization in PL (28.0 ± 3.44) and Lipo group (24.50 ± 3.06) at P17. Moreover, inhibitory effects maintained at P22 in PL group (11.70 ± 3.09) as HE staining showed. Fluorescein angiography of retinal vascular showed retinal non-perfusion and neovascularization areas were smaller in both PL and Lipo group at P17. Frozen-section examination showed the property of membrane translocation. GFP expression could be seen in vitreous cavity just at first day post-intravitreal administration in PL and Lipo group, which could reach their peaks in external retina nearby RPE layer at P17, remaining at P22 in PL group. CONCLUSION: The PL performed excellent ability of membrane translocation and it was a kind of slow steady released gene vector.

Ocular surface changes in type II diabetic patients with proliferative diabetic retinopathy.

AIM: To detect and analyze the changes on ocular surface and tear function in type II diabetic patients with proliferative diabetic retinopathy (PDR), an advanced stage of diabetic retinopathy (DR), using conventional ophthalmic tests and the high-resolution laser scanning confocal microscopy. METHODS: Fifty-eight patients with type II diabetes were selected. Based on the diagnostic criteria and stage classification of DR, the patients were divided into the non-DR (NDR) group and the PDR group. Thirty-six patients with cataract but no other ocular and systemic disease were included as non-diabetic controls. All the patients were subjected to the conventional clinical tests of corneal sensitivity, Schirmer I Test, and corneal fluorescein staining. The non-invasive tear film break-up time (NIBUT) and tear interferometry were conducted by a Tearscope Plus. The morphology of corneal epithelia and nerve fibers was examined using the high-resolution confocal microscopy. RESULTS: The NDR group exhibited significantly declined corneal sensitivity and Schirmer I test value, as compared to the non-diabetic controls (P< 0.001). The PDR group showed significantly reduced corneal sensitivity, Schirmer I test value, and NIBUT in comparison to the non-diabetic controls (P < 0.001). Corneal fluorescein staining revealed the progressively injured corneal epithelia in the PDR patients. Moreover, significant decrease in the corneal epithelial density and morphological abnormalities in the corneal epithelia and nerve fibers were also observed in the PDR patients. CONCLUSION: Ocular surface changes, including blunted corneal sensitivity, reduced tear secretion, tear film dysfunction, progressive loss of corneal epithelia and degeneration of nerve fibers, are common in type II diabetic patients, particularly in the diabetic patients with PDR. The corneal sensitivity, fluorescein staining scores, and the density of corneal epithelial cells and nerve fibers in the diabetic patients correlate with the duration of diabetes. Therefore, ocular surface of the patients with PDR should be examined regularly by conventional approaches and confocal microscopy to facilitate early diagnosis and treatment of keratopathy.

[Effect of lamellar keratoplasty time on the production of serum specific antibody in corneal alkali burns].

OBJECTIVE: To observe the production of serum specific anti-denatured corneal antibody and the effects of lamellar keratoplasty on changes of corneal histopathology in different stages after alkali burns. METHODS: 20 male New Zealand rabbits, with alkali burns in right eye were randomly divided into 5 groups including: burned group; 2 early lamellar keratoplasty group (operation at 3 or 7 days post alkali burns respectively); 2 middle and later lamellar keratoplasty groups (operation at 2 or 5 weeks after alkali burns respectively). The level of serum specific antibody in each group was detected by ELISA and the corneal structure was evaluated by light and electron microscopy in different stages after alkali burns. RESULTS: The anti-denatured corneal antibody was induced after corneal alkali burns. The level of antibody significantly increased at 2th week post, peaking burn at 5 or 6th week, then decreasing. More antibodies were detected when contralateral eye was burn at 8 week post first burn. However, only slight increasing antibody was detected in early lamellar keratoplasty group. Furthermore, no significant changes of antibody production were observed in middle and later lamellar keratoplasty group. The light and electron microscopic analysis showed that, the corneal epithelium recovered better, the fibre of corneal stroma arranged better, inflammatory cells infiltrated less and neovascularization formed less in lamellar keratoplasty groups comparing to the burned group. The early lamellar keratoplasty groups recovered better than in middle and later lamellar keratoplasty groups. CONCLUSION: Early lamellar keratoplasty after corneal alkali burns can significantly decrease the immune response. Histopathological data also indicate that early lamellar keratoplasty can improve the tissue regeneration and recovery, prevent topical inflammatory reaction, and abate corneal neovascularization. This study suggests that early lamellar keratoplasty is more effective than the conservative treatment.

Improvement of recombinant hirudin production by controlling NH4+ concentration in Pichia pastoris fermentation.

In recombinant Pichia pastoris fermentation for hirudin production in a 5 l fermenter, a new strategy was explored to match the short fermentation time at low NH4+ concentration with decreased hirudin degradation at high NH4+ concentration. A combination of a defined medium containing initial 0.025 m NH4+ with NH4+ addition up to 0.6 m in the growth phase was achieved in both the improvement of hirudin production and the repression of hirudin degradation. Intact and total hirudin reached 2.63 g l(-1) and 4.25 g l(-1), respectively.