Extracellular Matrix Formation Research Articles

Decellularized Caprine Conchal Cartilage toward Repair and Regeneration of Damaged Cartilage.

Repair and regeneration of nasal and auricular cartilage thrust significant challenges in reconstructive surgery. The burgeoning clinical requirement is yet to endorse a satisfactory cartilage replacement matrix. In this regard, we have bioengineered cross-linked decellularized caprine conchal cartilage (DC) as biocompatible, durable, and nontoxic matrices. The DC matrices exhibited reduced DNA and sulfated glycosaminoglycan (sGAG) with a minimal effect on the collagen content. Further, histology and scanning electron micrographs revealed a significant loss of cellular bodies and the presence of a compact matrix consisting of intricate collagen fibers, when compared to unprocessed matrices. An in vitro biological assessment of the matrices exhibited an increased chondrocyte proliferation and viability with a significantly higher DNA, sGAG, and total collagen content. The matrices showed a 3-fold increase in the expression of cartilage-specific genes, namely, aggrecan, collagen II, and sox-9, and exhibited a minimal in vitro immunogenicity. Further, an in vivo assessment was performed by xenografting these caprine matrices in a rabbit model. The retrieved matrices showed a well-organized structural and cellular orientation with extracellular matrix formation after 3 months of implantation. No significant infiltration of plasma cells, macrophages, lymphocytes, and immature fibroblasts was recorded. Therefore, these affordable, resourceful, xenocompatible matrices offer a potential alternate in the repair and regeneration of nasal and auricular cartilages.

Natural Antioxidant Resveratrol Suppresses Uterine Fibroid Cell Growth and Extracellular Matrix Formation In Vitro and In Vivo.

Resveratrol (RSV) is a polyphenolic phytoalexin found in peanuts, grapes, and other plants. Uterine fibroids (UF) are benign growths that are enriched in extracellular matrix (ECM) proteins. In this study, we aimed to investigate the effects of RSV on UF using in vivo and in vitro approaches. In mouse xenograft models, tumors were implanted through the subcutaneous injection of Eker rat-derived uterine leiomyoma cells transfected with luciferase (ELT-3-LUC) in five-week-old female nude (Foxn1nu) mice. When the tumors reached a size of 50–100 mm3, the mice were randomly assigned to intraperitoneal treatment with RSV (10 mg·kg−1) or vehicle control (dimethyl sulfoxide). Tumor tissues were assayed using an immunohistochemistry analysis. We also used primary human leiomyoma cells as in vitro models. Cell viability was determined using the sodium bicarbonate and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The protein expression was assayed using Western blot analysis. The messenger ribonucleic acid (mRNA) expression was assayed using quantitative reverse transcription–polymerase chain reaction (qRT–PCR). Cell apoptosis was assayed using Annexin V-fluorescein isothiocyanate (FITC) and propidium iodide (PI) and Hoechst 33342 staining. RSV significantly suppressed tumor growth in vivo and decreased the proportion of cells showing expression of proliferating cell nuclear antigen (PCNA) and α-smooth muscle actin (α-SMA). In addition, RSV decreased the protein expression of PCNA, fibronectin, and upregulated the ratio of Bax (Bcl-2-associated X) and Bcl-2 (B-cell lymphoma/leukemia 2) in vivo. Furthermore, RSV reduced leiomyoma cell viability, and decreased the mRNA levels of fibronectin and the protein expression of collagen type 1 (COL1A1) and α-SMA (ECM protein marker), as well as reducing the levels of β-catenin protein. RSV induced apoptosis and cell cycle arrest at sub-G1 phase. Our findings indicated the inhibitory effects of RSV on the ELT-3-LUC xenograft model and indicated that RSV reduced ECM-related protein expression in primary human leiomyoma cells, demonstrating its potential as an anti-fibrotic therapy for UF.

Impact of modified gelatin on valvular microtissues.

A significant challenge in the field of tissue engineering is the biofabrication of three-dimensional (3D) functional tissues with direct applications in organ-on-a-chip systems and future organ engineering. Multicellular valvular microtissues can be used as building blocks for the formation of larger scale valvular macrotissues. Yet, for the controlled biofabrication of 3D macrotissues with predefined complex shapes, directed assembly of microtissues through bioprinting is needed. This study aimed to investigate if modified gelatin is an instructive material for valvular microtissues. Valvular microtissues were encapsulated in modified gelatin hydrogels and cross-linked in the presence of a photoinitiator (Irgacure 2959 or VA-086). Hydrogel properties were determined, and valvular interstitial cell functions like phenotype, proliferation, migration, mRNA expression of extracellular matrix (ECM) molecules, ECM deposition, and tissue fusion were characterized by histochemical stainings and RT-qPCR. Encapsulated microtissues remained viable, produced heart valve-related ECM components, and remained in a quiescent state. However, encapsulation induced some changes in ECM formation and gene expression. Encapsulated microtissues showed lower remodeling capacity and increased expression levels of Col I/V, elastin, hyaluronan, biglycan, decorin, and Sox9 compared with nonencapsulated microtissues. Furthermore, this study demonstrated that proliferation, migration, and tissue fusion was more pronounced in softer gels. In general, we evidenced that modified gelatin is an instructive material for physiologically relevant valvular microtissues and provided a proof of concept for the formation of larger valvular tissue by assembling microtissues at random in soft gels.

Impact of Human Dermal Microvascular Endothelial Cells on Primary Dermal Fibroblasts in Response to Inflammatory Stress.

The aim of the present study was to evaluate the impact of the microenvironment produced by dermal microvascular endothelial cells, secondary to a pro-inflammatory challenge, on 2D culture models using dermal fibroblasts and in 3D reconstructed skin model using dermal fibroblasts and keratinocytes from healthy donors. We hypothesized that specific microvascular endothelial low grade inflammation could change fibroblasts phenotype and be involved in extracellular matrix (ECM) modification and skin alteration. Following IFNγ, TNFα, IL-1β pro-inflammatory stress on Human Dermal Endothelial Cells (HDMEC) we observed the increased release of Chemokine ligand 2 (CCL2), IL-6 and IL-8 but not VEGF-A in the conditioned medium (CM). The subsequent addition of this endothelial pro-inflammatory CM in dermal fibroblasts revealed an upregulation of IL6, IL8 and CCL2 but no NF-κB gene expression. The resulting ECM formation was impaired with a reduction of the collagen 1 network and a decrease in COL1A1 gene expression in 2D and 3D models. Collagen 1 and pro-LOX protein expression were significantly reduced confirming an impairment of the collagen network related to endothelial inflammation secretion. To conclude, this work showed that, without any immune cells, the endothelial secretion in response to a pro-inflammatory stress is able to activate the fibroblasts that will maintain the pro-inflammatory environment and exacerbate ECM degradation.

Matrix metalloproteinases in patients with resistant hypertension and type 2 diabetes mellitus: relation with renal blood flow and kidney function

Objective.To evaluate the plasma levels of metalloproteinases (MMP) and their inhibitor in patients with resistant hypertension (RHTN) and type 2 diabetes mellitus (DM2) and their relationship with renal blood flow and kidney function.Design and methods.The study included 18 patients with RHTN and DM2 and 16 individuals with RHTN without DM, who underwent offce and 24-h ambulatory blood pressure measurements, renal Doppler ultrasound, and laboratory tests (daily albuminuria, estimated glomerular fltration rate calculated by CKD-EPI formula, HbА1c and basal glycaemia levels, MMP-9, MMP-2, tissue inhibitor of MMP type 1 (TIMP1), MMP/TIMP-1 ratios).Results.Patients with RHTN and DM2 and subjects with RHTN without DM were comparable by mean levels of metalloproteinases, TIMP-1, and their ratios. The frequency of increased MMP-9 level was similar in both groups (61 % for RHTN + DM2 group and 75 % for RHTN without DM, p > 0,05). In patients with RHTN and DM2 the increase in MMP-9 and a decrease in TIMP-1/MMP-9 ratio were associated with a reduction in renal resistive indices (MMP-9 and RI in the main renal arteries: right-sided R = –0,60, p = 0,009, left-sided R = –0,60, p = 0,008; in segmental arteries: R = –0,49, p = 0,038 on the right and R = –0,59, p = 0,012 on the left; for TIMP-1/MMP-9 and segmental arteries: R = 0,51, p = 0,028 on the right; and R = 0,46, p = 0,04 on the left). The eGFR and MMP-9 signifcantly correlated (R = 0,55, p = 0,023). Patients with increased albuminuria showed higher values of TIMP-1/MMP-2 ratio than patients with normal albuminuria (2,97 ± 0,82 и 1,58 ± 0,33 ng/mL, respectively, p = 0,03). There was a direct correlation between TIMP-1/MMP-2 ratio and basal glycaemia (R = 0,59, p = 0,018).Conclusions.Patients with RHTN and DM2 had comparable MMP levels and their inhibitor to those in patients with RHTN without DM, which may partly reflect that extracellular matrix formation is independent from carbohydrate disorders in RHTN. In patients with RHTN and DM2 an increase in MMP-9 and a decrease in TIMP-1/MMP-9 ratio may be adaptive, since it is accompanied by improved intrarenal blood flow and renal fltration function. The increase in basal hyperglycemia is associated with the suppression of the proteolytic activity of MMP-2 related to the progression of albuminuria.

Photopolymerizable gelatin and hyaluronic acid for stereolithographic 3D bioprinting of tissue-engineered cartilage.

To create artificial cartilage in vitro, mimicking the function of native extracellular matrix (ECM) and morphological cartilage‐like shape is essential. The interplay of cell patterning and matrix concentration has high impact on the phenotype and viability of the printed cells. To advance the capabilities of cartilage bioprinting, we investigated different ECMs to create an in vitro chondrocyte niche. Therefore, we used methacrylated gelatin (GelMA) and methacrylated hyaluronic acid (HAMA) in a stereolithographic bioprinting approach. Both materials have been shown to support cartilage ECM formation and recovery of chondrocyte phenotype. We used these materials as bioinks to create cartilage models with varying chondrocyte densities. The models maintained shape, viability, and homogenous cell distribution over 14 days in culture. Chondrogenic differentiation was demonstrated by cartilage‐typical proteoglycan and type II collagen deposition and gene expression (COL2A1, ACAN) after 14 days of culture. The differentiation pattern was influenced by cell density. A high cell density print (25 × 106 cells/mL) led to enhanced cartilage‐typical zonal segmentation compared to cultures with lower cell density (5 × 106 cells/mL). Compared to HAMA, GelMA resulted in a higher expression of COL1A1, typical for a more premature chondrocyte phenotype. Both bioinks are feasible for printing in vitro cartilage with varying differentiation patterns and ECM organization depending on starting cell density and chosen bioink. The presented technique could find application in the creation of cartilage models and in the treatment of articular cartilage defects using autologous material and adjusting the bioprinted constructs size and shape to the patient. © 2019 The Authors. Journal of Biomedical Materials Research Part B: Applied Biomaterials published by Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B:2649–2657, 2019.

Whole-Exome Sequencing in the Isolated Populations of Cilento from South Italy

The present study describes the genetic architecture of the isolated populations of Cilento, through the analysis of exome sequence data of 245 representative individuals of these populations. By annotating the exome variants and cataloguing them according to their frequency and functional effects, we identified 347,684 variants, 67.4% of which are rare and low frequency variants, and 1% of them (corresponding to 319 variants per person) are classified as high functional impact variants; also, 39,946 (11.5% of the total) are novel variants, for which we determined a significant enrichment for deleterious effects. By comparing the allele frequencies in Cilento with those from the Tuscan population from the 1000 Genomes Project Phase 3, we highlighted an increase in allele frequency in Cilento especially for variants which map to genes involved in extracellular matrix formation and organization. Furthermore, among the variants showing increased frequency we identified several known rare disease-causing variants. By different population genetics analyses, we corroborated the status of the Cilento populations as genetic isolates. Finally, we showed that exome data of Cilento represents a useful local reference panel capable of improving the accuracy of genetic imputation, thus adding power to genetic studies of human traits in these populations.

Genetic Disorders of the Extracellular Matrix.

ABSTRACTMutations in the genes for extracellular matrix (ECM) components cause a wide range of genetic connective tissues disorders throughout the body. The elucidation of mutations and their correlation with pathology has been instrumental in understanding the roles of many ECM components. The pathological consequences of ECM protein mutations depend on its tissue distribution, tissue function, and on the nature of the mutation. The prevalent paradigm for the molecular pathology has been that there are two global mechanisms. First, mutations that reduce the production of ECM proteins impair matrix integrity largely due to quantitative ECM defects. Second, mutations altering protein structure may reduce protein secretion but also introduce dominant negative effects in ECM formation, structure and/or stability. Recent studies show that endoplasmic reticulum (ER) stress, caused by mutant misfolded ECM proteins, makes a significant contribution to the pathophysiology. This suggests that targeting ER‐stress may offer a new therapeutic strategy in a range of ECM disorders caused by protein misfolding mutations. Anat Rec, 2019. © 2019 The Authors. The Anatomical Record published by Wiley Periodicals, Inc. on behalf of American Association of Anatomists.

Wound healing in post-smolt Atlantic salmon (Salmo salar L.)

Skin biopsies (5 mm) taken from behind the dorsal fin on Atlantic salmon post-smolts were followed over a 2 month period. The healing process was dominated by hemostasis, acute inflammation, and epidermal repair the first 14 days post wounding (dpw), as shown through imaging, histological evaluation, and transcriptomics. Most of the immune genes showed decreased expression after two weeks, approaching the levels of intact skin, as also reflected in sections where reduced inflammation in the wound bed was observed. Transcriptional events suggest recruitment of lymphocytes to the wound site during the acute phase, with activation of humoral responses from 14 dpw and onward. From the histology, a more adherent mucus was observed that correlated with altered transcription of glycosyltransferases. This may indicate different properties and functions of the mucus during the wound healing process. Wound contraction started between 14 and 36 dpw. The occurrence of these events was concurrent with granulation tissue formation, melanocyte migration and up-regulation of genes involved in extracellular matrix formation. The presented description of the wound healing processes in Atlantic salmon gives insight into comparative ulcerative biology in mammals and fish and provides both novel and updated knowledge that can be applied for improved best operational practices for fish welfare in aquaculture.

Raw and vinegar processed Curcuma wenyujin regulates hepatic fibrosis via bloking TGF-β/Smad signaling pathways and up-regulation of MMP-2/TIMP-1 ratio.

Curcuma wenyujin Y.H. (CW), a variety of Curumae Rhizoma, which documented in China Pharmacopeia, has long been used as plant medicine for its traditional effect on promoting Qi, activating blood stagnation and expelling blood stasis. Nowadays, it is often used in clinic for extraordinary effect on liver diseases. It is worthy to be noted that CW processed with vinegar has been applied in clinic for 1500 years which started in the northern and southern dynasties. Liver fibrosis is a worldwide clinical issue. It is worth developing a multi-target and multicellular approach which is high efficiency and low side effects for the treatment of hepatic fibrosis. The anti-hepatic fibrosis molecular mechanisms of CW and vinegar Curcuma wenyujin (VCW) need to be explored and elucidated. Furthermore, the study aimed to discuss the efficiency and mechanism differences between CW and VCW in hepatic fibrosis. Biochemical assays and histopathology were adopted to evaluate the anti-hepatic fibrosis effect of CW and VCW. The TGF-β/Smad signaling involving TGF-β1, TGF-βRⅠ, TGF-βRⅡ and Smad2, Smad3, Smad7 in fibrosis is examined, which is a critical step towards the evaluation of anti-hepatic fibrosis agents. Meanwhile, the MMP/TIMP balance is a potential therapy target by modulating extracellular matrix, which is also examined. Both CW and VCW inhibit the activation and proliferation of hepatic stellate cells and induce apoptosis via blocking TGF-β/Smad signaling pathways. Additionally, the level of MMP-2/TIMP-1 regulated significantly, which suggest CW and VCW participate in the degradation process, and maintain the formation and production of extracellular matrix. Raw and vinegar processed Curcuma wenyujin regulates hepatic fibrosis via bloking TGF-β/Smad signaling pathways and up-regulation of MMP-2/TIMP-1 ratio. And VCW has more exhibition than CW.

Chondrogenic differentiation of mouse induced pluripotent stem cells using the three-dimensional culture with ultra-purified alginate gel.

As articular cartilages have rarely healed by themselves because of their characteristics of avascularity and low cell density, surgical intervention is ideal for patients with cartilaginous injuries. Because of structural characteristics of the cartilage tissue, a three-dimensional culture of stem cells in biomaterials is a favorable system on cartilage tissue engineering. Induced pluripotent stem cells (iPSCs) are a new cell source in cartilage tissue engineering for its characteristics of self-renewal capability and pluripotency. However, the optimal cultivation condition for chondrogenesis of iPSCs is still unknown. Here we show that a novel chondrogenic differentiation method of iPSCs using the combination of three-dimensional cultivation in ultra-purified alginate gel (UPAL gel) and multi-step differentiation via mesenchymal stem cell-like cells (iPS-MSCs) could efficiently and specifically differentiate iPSCs into chondrocytes. The iPS-MSCs in UPAL gel culture sequentially enhanced the expression of chondrogenic marker without the upregulation of that of osteogenic and adipogenic marker and histologically showed homogeneous chondrogenic extracellular matrix formation. Our results suggest that the pluripotency of iPSCs can be controlled when iPSCs are differentiated into iPS-MSCs before embedding in UPAL gel. These results lead to the establishment of an efficient three-dimensional system to engineer artificial cartilage tissue from iPSCs for cartilage regeneration. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 107A: 1086-1093, 2019.

Enhancing X-ray Attenuation of 3D Printed Gelatin Methacrylate (GelMA) Hydrogels Utilizing Gold Nanoparticles for Bone Tissue Engineering Applications.

Bone tissue engineering is a rapidly growing field which is currently progressing toward clinical applications. Effective imaging methods for longitudinal studies are critical to evaluating the new bone formation and the fate of the scaffolds. Computed tomography (CT) is a prevailing technique employed to investigate hard tissue scaffolds; however, the CT signal becomes weak in mainly-water containing materials, which hinders the use of CT for hydrogels-based materials. Nevertheless, hydrogels such as gelatin methacrylate (GelMA) are widely used for tissue regeneration due to their optimal biological properties and their ability to induce extracellular matrix formation. To date, gold nanoparticles (AuNPs) have been suggested as promising contrast agents, due to their high X-ray attenuation, biocompatibility, and low toxicity. In this study, the effects of different sizes and concentrations of AuNPs on the mechanical properties and the cytocompatibility of the bulk GelMA-AuNPs scaffolds were evaluated. Furthermore, the enhancement of CT contrast with the cytocompatible size and concentration of AuNPs were investigated. 3D printed GelMA and GelMA-AuNPs scaffolds were obtained and assessed for the osteogenic differentiation of mesenchymal stem cells (MSC). Lastly, 3D printed GelMA and GelMA-AuNPs scaffolds were scanned in a bone defect utilizing µCT as the proof of concept that the GelMA-AuNPs are good candidates for bone tissue engineering with enhanced visibility for µCT imaging.

Proof of Concept on Functionality Improvement of Mesenchymal Stem-Cells, in Postmenopausal Osteoporotic Women Treated with Teriparatide (PTH1-34), After Suffering Atypical Fractures.

Osteoporosis long-term treatment with nitrogen-containing bisphosphonates, has been associated with uncommon adverse effects, as atypical femoral fractures (AFF). Thus, treatment with teriparatide (TPTD; fragment of human parathyroid hormone; PTH1-34) has been proposed for such patients. Besides its anabolizing effect on bone, TPTD may affect stem-cell mobilization and expansion. Bone marrow mononuclear cells (BMMNC) were isolated from five women that had suffered AFF associated to bisphosphonate treatment, before and after 6months of TPTD therapy. The presence of mesenchymal stromal cells (CD73, CD90 and CD105 positive cells), gene expression of NANOG, SOX2 and OCT4, proliferation, senescence and capacity to differentiate into osteoblasts and adipocytes were analyzed. After TPTD treatment, BMMNC positive cells for CD73, CD90 and CD105 increased from 6.5 to 37.5% (p < 0.05); NANOG, SOX2 and OCT4 were upregulated, being statistically significant for NANOG (p < 0.05), and cells increased proliferative capacity more than 50% at day 7 (p < 0.05). Senescence was reduced 2.5-fold (p < 0.05), increasing differentiation capacity into osteoblasts and adipocytes, with more than twice mineralization capacity of extracellular matrix or fat-droplet formation (p < 0.05), respectively. Results show that TPTD treatment caused BMMNC "rejuvenation", increasing the number of cells in a more undifferentiated stage, with higher differentiation potency. This effect may favor TPTD anabolic action on bone in such patients with AFF, increasing osteoblast precursor cells. Such response could also arise in other osteoporotic patients treated with TPTD, without previous AFF. Furthermore, our data suggest that TPTD effect on stromal cells may have clinical implications for bone-regenerative medicine. Further studies may deepen on this potential.

Increase of Tumor Infiltrating γδ T-cells in Pancreatic Ductal Adenocarcinoma Through Remodeling of the Extracellular Matrix by a Hyaluronan Synthesis Suppressor, 4-Methylumbelliferone.

Desmoplastic changes of extracellular matrix (ECM) containing large amounts of hyaluronan (HA) are of interest in chemo- and immunoresistance of pancreatic ductal adenocarcinoma (PDAC). The goal of this study was to evaluate the effects of 4-methylumbelliferone (MU), a selective inhibitor of HA, on ECM and to examine how MU affects adoptive immunotherapy. The effect of MU on cell proliferation, HA synthesis and formation of ECM were investigated in four PDAC cell lines. In addition, the cytotoxicity of γδ T-cell-rich peripheral blood mononuclear cells (PBMCs) collected from healthy donors and stimulated with zoledronate and interleukin-2 was examined in the presence of MU. The amount of HA and tumor-infiltrating lymphocytes were also investigated in mice xenograft models. In vitro, 1.0 mM MU inhibited cell proliferation by 45-70% and HA synthesis by 55-80% in all four PDAC cell lines, and enhanced γδ T-cell-rich PBMC-mediated cytotoxicity against PDAC cells. In vivo, MU reduced intratumoral HA and promoted infiltration of inoculated γδ T-cells into tumor tissue, and consequently suppressed tumor growth. 4-methylumbelliferone may be an effective immunosensitizer against PDAC through induction of structural changes in the ECM.

Tissue Regeneration of Human Mesenchymal Stem Cells on Porous Gelatin Micro-Carriers by Long-Term Dynamic In Vitro Culture.

Tissue engineering is a multidisciplinary field which attracted much attention in recent years. One of the most important issue in tissue engineering is how to obtain high cell numbers and tissue regeneration while maintaining appropriate cellular characteristics in vitro for restoring damaged or dysfunctional body tissues and organs. These demands can be achieved by the use of three dimensional (3D) dynamic cultures of cells combined with cell-adhesive micro-carriers. In this study, human mesenchymal stem cells (hMSCs) were cultured in a wave-bioreactor system for up to 100days, after seeding on Cultisphere-S porous gelatin micro-carriers. Cell counting was performed at the time points of 7, 12, 17, 31days and compared to those of hMSCs cultured under static condition. Higher growth and proliferation rates was achieved in wave-type dynamic culture, when cell culture continued to day 31. A scanning electron microscope (SEM) photographs, both live and dead and MTT assays were taken to confirm the survival and distribution of cells on porous gelatin micro-carrier surfaces. The results of histological stains such as hematoxylin and eosin, Masson's trichrome, Alcian blue and Alizarin red S also showed improved proliferation and tissue regeneration of hMSCs on porous gelatin micro-carriers. The experimental results demonstrated the effect and importance of both micro-carriers and bioreactor in hMSC expansion on cell proliferation and migration as well as extracellular matrix formation on the superficial and pore surfaces of the porous gelatin micro-carriers, and then their inter-connections, leading to tissue regeneration.

A Young Boy with Multiple Bony Overgrowths

Hereditary multiple exostoses is a rare autosomal dominant pediatric disorder with an incidence of about 1:50000 characterized by multiple cartilage-capped bony protuberances, called osteochondromas or exostoses, projecting from the metaphyses of long bones. It is caused by loss of function mutations in exostosin-1 and exostosin-2 genes that encode glycosyltransferase enzymes involved in the synthesis of heparan sulfate which has fundamental role in extracellular matrix formation during bone development. It commonly presents with compressive symptoms due to bony overgrowth involving all bones except calvarium and rarely transformed into malignancy. No definite treatment is available, but careful screening of these exostoses with timely referral to respective surgeon prevents long term complications and improves quality of life.&#x0D; J Enam Med Col 2019; 9(1): 60-63

Nanomaterials in Craniofacial Tissue Regeneration: A Review

Nanotechnology is an exciting and innovative field when combined with tissue engineering, as it offers greater versatility in scaffold design for promoting cell adhesion, proliferation, and differentiation. The use of nanomaterials in craniofacial tissue regeneration is a newly developing field that holds great potential for treating craniofacial defects. This review presents an overview of the nanomaterials used for craniofacial tissue regeneration as well as their clinical applications for periodontal, vascular (endodontics), cartilage (temporomandibular joint), and bone tissue regeneration (dental implants and mandibular defects). To enhance periodontal tissue regeneration, nanohydroxyapatite was used in conjunction with other scaffold materials, such as polylactic acid, poly (lactic-co-glycolic acid), polyamide, chitosan, and polycaprolactone. To facilitate pulp regeneration along with the revascularization of the periapical tissue, polymeric nanofibers were used to simulate extracellular matrix formation. For temporomandibular joint (cartilage) engineering, nanofibrous-type and nanocomposite-based scaffolds improved tissue growth, cell differentiation, adhesion, and synthesis of cartilaginous extracellular matrix. To enhance bone regeneration for dental implants and mandibular bone defects, nanomaterials such as nanohydroxyapatite composite scaffolds, nanomodified mineral trioxide aggregate, and graphene were tested. Although the scientific knowledge in nanomaterials is rapidly advancing, there remain many unexplored data regarding their standardization, safety, and interactions with the nanoenvironment.

Superior silybin bioavailability of silybin\u2013phosphatidylcholine complex in oily-medium soft-gel capsules versus conventional silymarin tablets in healthy volunteers*

BackgroundFibrosis is a response to chronic liver disease that results in excessive accumulation of extracellular matrix proteins and formation of scar tissue. Fibrosis represents a clinical challenge of worldwide significance. Several studies have demonstrated that many natural products and herbal medicines have activity against liver fibrosis, and extracts of milk thistle such as silymarin and silybin are the natural compounds most commonly prescribed for liver diseases. Therefore, we sought to assess and compare the pharmacokinetic properties and bioavailability of silybin–phosphatidylcholine complex in oily-medium soft-gel capsules and conventional silymarin tablets in healthy Mexican volunteers.MethodsWe enrolled 23 healthy volunteers to participate in a prospective, balanced, blind, single-dose, two-way crossover study with a one-week washout period. Fasting participants received either 45 mg silybin–phosphatidylcholine complex or 70 mg silymarin to assess which formulation provided better bioavailability of silybin. Plasma was obtained and analysed for silybin concentration using a validated ultra-performance liquid chromatography–tandem mass spectroscopy method. Pharmacokinetic parameters were obtained by non-compartmental analysis and values were compared by analysis of variance for a crossover design. Ratios of maximum plasma drug concentration and area under the curve (AUC) were obtained and 90% confidence intervals were calculated.ResultsThe 23 healthy subjects (11 women, 12 men) who participated in the study were aged 22–31 years old (average: 28), average weight 64.8 kg, height 1.65 m and body mass index 23.5 kg/m2. Plasma levels of silybin were higher after the administration of silybin–phosphatidylcholine complex capsules compared with that after conventional silymarin tablets (P < 0.0001).ConclusionsThe silybin–phosphatidylcholine complex in oily-medium soft-gel capsules seems to provide superior bioavailability. However, clinical studies must be performed to demonstrate its clinical relevance in the treatment of liver diseases.Trial registrationNCT03440164; registered on November 11, 2016.

Formation of Neoarteries with Optimal Remodeling Using Rapidly Degrading Textile Vascular Grafts.

We utilized innovative textile technology to create tissue-engineered vascular grafts (TEVGs) comprised exclusively of rapidly degrading material poly(glycolic acid). Our new technology led to robust neotissue formation in the TEVGs, especially extracellular matrix formation, such as elastin. In addition, the rapid degradation of the polymer significantly reduced complications, such as stenosis or calcification, as seen with the use of slow degrading polymers in the majority of previous studies for aortic small diameter TEVGs.

Mechanical performance of gelatin fiber mesh scaffolds reinforced with nano-hydroxyapatite under bone damage mechanisms

Engineered tissues scaffolds should be design to mimic, at least partially, the extracellular matrix (ECM) in native tissues. Our scaffold's design satisfies, important challenges among the implant architecture requirements: (i) a fiber mesh entanglement mimicking physical attributes of natural ECM; (ii) a nanostructure surface roughness and chemical cues to increase the interaction with host tissue; (iii) a hydrolytic and enzymatic biodegradability; (iv) an open interconnected macroporosity to promote highly permeability and (v) a tensile stability under mechanical damage mechanisms. These properties are very important for cell seeding, adhesion, vascularization, new ECM formation and the subsequent tissue regeneration.