Chemical and structural changes of pretreated empty fruit bunch (EFB) in ionic liquid-cellulase compatible system for fermentability to bioethanol

The pretreatment of empty fruit bunch (EFB) was conducted using an integrated system of IL and cellulases (IL-E), with simultaneous fermentation in one vessel. The cellulase mixture (PKC-Cel) was derived from Trichoderma reesei by solid-state fermentation. Choline acetate [Cho]OAc was utilized for the pretreatment due to its biocompatibility and biodegradability. The treated EFB and its hydrolysate were characterized by the Fourier transform infrared spectroscopy, scanning electron microscopy, and chemical analysis. The results showed that there were significant structural changes in EFB after the treatment in IL-E system. The sugar yield after enzymatic hydrolysis by the PKC-Cel was increased from 0.058 g/g of EFB in the crude sample (untreated) to 0.283 and 0.62 ± 06 g/g in IL-E system after 24 and 48 h of treatment, respectively. The EFB hydrolysate showed the eligibility for ethanol production without any supplements where ethanol yield was 0.275 g ethanol/g EFB in the presence of the IL, while lower yield obtained without IL-pretreatment. Moreover, it was demonstrated that furfural and phenolic compounds were not at the level of suppressing the fermentation process

Enhancing methane production from lignocellulosic biomass by combined steam‑explosion pretreatment and bioaugmentation with cellulolytic bacterium Caldicellulosiruptor bescii

Background: Biogas production from lignocellulosic biomass is generally considered to be challenging due to the recalcitrant nature of this biomass. In this study, the recalcitrance of birch was reduced by applying steam-explosion (SE) pretreatment (210 °C and 10 min). Moreover, bioaugmentation with the cellulolytic bacterium Caldicellulosiruptor bescii was applied to possibly enhance the methane production from steam-exploded birch in an anaerobic digestion (AD) process under thermophilic conditions (62 °C). Results: Overall, the combined SE and bioaugmentation enhanced the methane yield up to 140% compared to untreated birch, while SE alone contributed to the major share of methane enhancement by 118%. The best methane improvement of 140% on day 50 was observed in bottles fed with pretreated birch and bioaugmentation with lower dosages of C. bescii (2 and 5% of inoculum volume). The maximum methane production rate also increased from 4-mL CH4/ g VS (volatile solids)/day for untreated birch to 9-14-mL CH4/ g VS/day for steam-exploded birch with applied bioaugmentation. Bioaugmentation was particularly effective for increasing the initial methane production rate of the pretreated birch yielding 21-44% more methane than the pretreated birch without applied bioaugmentation. The extent of solubilization of the organic matter was increased by more than twofold when combined SE pretreatment and bioaugmentation was used in comparison with the methane production from untreated birch. The beneficial effects of SE and bioaugmentation on methane yield indicated that biomass recalcitrance and hydrolysis step are the limiting factors for efficient AD of lignocellulosic biomass. Microbial community analysis by 16S rRNA amplicon sequencing showed that the microbial community composition was altered by the pretreatment and bioaugmentation processes. Notably, the enhanced methane production by pretreatment and bioaugmentation was well correlated with the increase in abundance of key bacterial and archaeal communities, particularly the hydrolytic bacterium Caldicoprobacter, several members of syntrophic acetate oxidizing bacteria and the hydrogenotrophic Methanothermobacter. Conclusion: Our findings demonstrate the potential of combined SE and bioaugmentation for enhancing methane production from lignocellulosic biomass

Fat Graft Retention: Adipose Tissue, Adipose-derived Stem Cells and Aging

Over the past 30 years, there has been a dramatic increase in the use of autologous fat grafting for soft-tissue augmentation and to improve facial skin quality. Several studies have highlighted the impact of aging on adipose tissue, leading to a decrease of adipose tissue volume and preadipocytes proliferation and increase of fibrosis. Recently, there has been a rising interest in adipose tissue components, including Adipose-derived Stem/Stromal Cells (ASCs) due to their regenerative potential, including inflammation, fibrosis and vascularization modulation. Due to their differentiation potential and paracrine function, ASC has been largely used for fat grafting procedures as they are described to be a key component in fat graft survival. However, many parameters as surgical procedures of adipose tissue biology could change clinical outcomes. Variation on fat grafting methods lead to numerous inconsistent clinical outcomes. Donor-to-donor variation could also be imputed to ASCs, tissue inflammatory state or tissue origin. In this review, we aim to analyze (1) the parameters involved on the graft survival, and (2) the effect of aging on adipose tissue components, especially ASCs, that could lead to a decrease of skin regeneration and fat graft retention

Fat Graft Retention: Adipose Tissue, Adipose-derived Stem Cells and Aging

Over the past 30 years, there has been a dramatic increase in the use of autologous fat grafting for soft-tissue augmentation and to improve facial skin quality. Several studies have highlighted the impact of aging on adipose tissue, leading to a decrease of adipose tissue volume and preadipocytes proliferation and increase of fibrosis. Recently, there has been a rising interest in adipose tissue components, including Adipose-derived Stem/Stromal Cells (ASCs) due to their regenerative potential, including inflammation, fibrosis and vascularization modulation. Due to their differentiation potential and paracrine function, ASC has been largely used for fat grafting procedures as they are described to be a key component in fat graft survival. However, many parameters as surgical procedures of adipose tissue biology could change clinical outcomes. Variation on fat grafting methods lead to numerous inconsistent clinical outcomes. Donor-to-donor variation could also be imputed to ASCs, tissue inflammatory state or tissue origin. In this review, we aim to analyze (1) the parameters involved on the graft survival, and (2) the effect of aging on adipose tissue components, especially ASCs, that could lead to a decrease of skin regeneration and fat graft retention

RECONSTRUCTION OF A FULL-THICKNESS COLLAGEN-BASED HUMAN ORAL MUCOSAL EQUIVALENT

Tissue engineered human oral mucosa has the potential to be applied to the closure of surgical wounds after tissue deficits due to facial trauma, malignant lesion surgery or preposthetic procedure. It can also be used to elucidate the biology and pathology of oral mucosa and as a model alternative to animals for safety testing of oral care products. Using the technology previously developed in our laboratory for the production of a skin equivalent, we were able to reconstruct a nonkeratinized full-thickness human oral mucosal equivalent closely mimicking human native oral mucosa. The successive coculture of human lamina propria fibroblasts and human oral epithelial cells isolated from the nonkeratinized region of oral cavity in a porous collagen–glycosaminoglycan (GAG)–chitosan scaffold gave rise to a lamina propria equivalent (LPE) and then to an oral mucosa equivalent (OME). The results of the histology, immunohistology and transmission electron microscopy of this OME demonstrated the presence of a nonkeratinized pluristratified and differentiated epithelium as in native nonkeratinized human oral mucosa expressing both K13 and K3/76. This epithelium was firmly anchored to the LPE by a continuous and ultrastructurally well-organized basement membrane. In the LPE, fibroblasts synthesized new extracellular matrix where the average collagen fibre diameter was 28.4 nm, close to that of native oral mucosa. The proliferative capacity of the basal cells was demonstrated by the expression of Ki6

A Simple Way to Reconstruct a Human 3-D Hypodermis: A Useful Tool for Pharmacological Functionality

International audienceBackground: Adipose tissue engineering has been hampered by the inability to culture mature adipocytes. Adipose-derived stem cell (ASC) culture opens the way for the preparation of human 3-D hypodermis in large quantities. These models play a role in obesity-related active molecules and slimming agent screening. Moreover, they contribute to a better understanding of the mechanisms underpinning obesity. Materials and Methods: Freshly extracted ASC from fat tissue were characterized by flow cytometry for CD73, CD90, CD105, HLA-ABC, CD14 and CD45 markers and by Western blot for pref-1. Their differentiation in mature adipocytes was followed by lipid and adiponectin secretion or by oil red O staining and radioimmunoassay. Neosynthesized extracellular matrix (ECM) of 3-D hypodermis was investigated by immunohistochemistry (collagen type I, V and VI) and transmission electron microscopy. Results: Our results demonstrate that the culture of preadipocytes in proliferation medium for 15 days followed by 16 days of culture in differentiation medium allowed production of the thickest single-layer hypodermis in which preadipocytes and mature adipocytes coexist and synthesize adiponectin and ECM components. Functionality of our 3-D single-layer hypodermis was demonstrated both by a 3.5-fold glycerol production after its stimulation with norepinephrine (adrenergic agonist) and by its slimming after caffeine treatment versus the nontreated 3-D hypodermis. Conclusion: This economic 3-D model, easy to prepare and giving reproducible results after the treatment of actives, is useful for pharmacotoxicological trials as an alternative to animal experimentation. Copyright (C) 2011 S. Karger AG, Base

3-D human hypodermis: morphology and functionality

National audienc

Encapsulation of Adipose-Derived Mesenchymal Stem Cells in Calcium Alginate Maintains Clonogenicity and Enhances their Secretory Profile

International audienceAdipose-derived mesenchymal stem cells (ASCs) are well known for their secretory potential, which confers them useful properties in cell therapy. Nevertheless, this therapeutic potential is reduced after transplantation due to their short survival in the human body and their migration property. This study proposes a method to protect cells during and after injection by encapsulation in microparticles of calcium alginate. Besides, the consequences of encapsulation on ASC proliferation, pluripotential, and secretome were studied. Spherical particles with a mean diameter of 500 µm could be obtained in a reproducible manner with a viability of 70% after 16 days in vitro. Moreover, encapsulation did not alter the proliferative properties of ASCs upon return to culture nor their differentiation potential in adipocytes, chondrocytes, and osteocytes. Concerning their secretome, encapsulated ASCs consistently produced greater amounts of interleukin-6 (IL-6), interleukin-8 (IL-8), and vascular endothelial growth factor (VEGF) compared to monolayer cultures. Encapsulation therefore appears to enrich the secretome with transforming growth factor β1 (TGF-β1) and macrophage inflammatory protein-1β (MIP-1β) not detectable in monolayer cultures. Alginate microparticles seem sufficiently porous to allow diffusion of the cytokines of interest. With all these cytokines playing an important role in wound healing, it appears relevant to investigate the impact of using encapsulated ASCs on the wound healing process

Eye bank prepared versus surgeon cut endothelial graft tissue for Descemet membrane endothelial keratoplasty: An observational study

International audienc

Impact du secrétome adipocytaire sur l’hormonothérapie dans le cancer du sein en situation de surpoids/obésité

National audienceL’obésité, facteur de risque établi de cancer du sein chez les femmes ménopausées, est aussi responsable de plus forts taux de récidives et de mortalité. Dans ce contexte, nos travaux évaluent l’impact du secrétome adipocytaire (SA) dans la moindre réponse à l’hormonothérapie. Pour cela, 1/ des cellules cancéreuses mammaires ont été soit co-cultivées avec des cellules souches adipeuses (CSAd) humaines (hMAD) différenciées en adipocytes matures (AM) soit cultivées en présence de milieux conditionnés (MC), puis traitées avec un anti-estrogène (anti-E ; Tamoxifène Tx ou Fulvestrant Fv). La prolifération cellulaire a été mesurée par fluorescence à la résazurine (Fluoroskan Ascent FL®, n=3) et suivie en temps réel par impédancemétrie (iCELLigence, n=3). 2/ L’impact du surpoids a été évalué en utilisant des AM différenciés à partir de CSAd de femmes minces ou obèses cultivées en présence de cellules MCF-7 et de Fv. Dans nos différents modèles, les SA sont capables de majorer la prolifération des cellules MCF-7, récepteur aux estrogènes positives (RE+), et d’inhiber totalement l’effet antiprolifératif du Tx et du Fv. L’utilisation de cellules MDA-MB-231 RE- a montré que le SA majore la prolifération cellulaire et contrecarre l’effet antiprolifératif du Tx, suggérant que les effets observés ne passeraient pas exclusivement par la voie du RE dans notre modèle. Par ailleurs, en utilisant des AM de femmes de poids variables, seuls les SA correspondant aux femmes d’IMC>30 amoindrissent l’efficacité du Fv, cet effet s’accompagnant d’une augmentation de l’expression du gène OB-R. Ainsi, nos résultats préliminaires suggèrent que le SA limiterait l’efficacité de l’hormonothérapie et ce, de façon plus prononcée en cas de surpoids, ce qui pourrait contribuer au processus d’échappement tumora