Matrix For Tissue Engineering Research Articles

Glycosaminoglycans Modulate the Angiogenic Ability of Type I Collagen-Based Scaffolds by Acting on Vascular Network Remodeling and Maturation.

Type I collagen, prevalent in the extracellular matrix, is biocompatible and crucial for tissue engineering and wound healing, including angiogenesis and vascular maturation/stabilization as required processes of newly formed tissue constructs or regeneration. Sometimes, improper vascularization causes unexpected outcomes. Vascularization failure may be caused by extracellular matrix collagen and non-collagen components heterogeneously. This study compares the angiogenic potential of collagen type I-based scaffolds and collagen type I/glycosaminoglycans scaffolds by using the chick embryo chorioallantoic membrane (CAM) model and IKOSA digital image analysis. Two clinically used biomaterials, Xenoderm (containing type I collagen derived from decellularized porcine extracellular matrix) and a dual-layer collagen sponge (DLC, with a biphasic composition of type I collagen combined with glycosaminoglycans) were tested for their ability to induce new vascular network formation. The AI-based IKOSA app enhanced the research by calculating from stereomicroscopic images angiogenic parameters such as total vascular area, branching sites, vessel length, and vascular thickness. The study confirmed that Xenoderm caused a fast angiogenic response and substantial vascular growth, but was unable to mature the vascular network. DLC scaffold, in turn, produced a slower angiogenic response, but a more steady and organic vascular maturation and stabilization. This research can improve collagen-based knowledge by better assessing angiogenesis processes. DLC may be preferable to Xenoderm or other materials for functional neovascularization, according to the findings.

Fabrication of a Novel 3D Extrusion Bioink Containing Processed Human Articular Cartilage Matrix for Cartilage Tissue Engineering.

Cartilage damage presents a significant clinical challenge due to its intrinsic avascular nature which limits self-repair. Addressing this, our study focuses on an alginate-based bioink, integrating human articular cartilage, for cartilage tissue engineering. This novel bioink was formulated by encapsulating C20A4 human articular chondrocytes in sodium alginate, polyvinyl alcohol, gum arabic, and cartilage extracellular matrix powder sourced from allograft femoral condyle shavings. Using a 3D bioprinter, constructs were biofabricated and cross-linked, followed by culture in standard medium. Evaluations were conducted on cellular viability and gene expression at various stages. Results indicated that the printed constructs maintained a porous structure conducive to cell growth. Cellular viability was 87% post printing, which decreased to 76% after seven days, and significantly recovered to 86% by day 14. There was also a notable upregulation of chondrogenic genes, COL2A1 (p = 0.008) and SOX9 (p = 0.021), suggesting an enhancement in cartilage formation. This study concludes that the innovative bioink shows promise for cartilage regeneration, demonstrating substantial viability and gene expression conducive to repair and suggesting its potential for future therapeutic applications in cartilage repair.

Cornea-Specific Human Adipose Stem Cell-Derived Extracellular Matrix for Corneal Stroma Tissue Engineering.

Utilizing tissue-specific extracellular matrices (ECMs) is vital for replicating the composition of native tissues and developing biologically relevant biomaterials. Human- or animal-derived donor tissues and organs are the current gold standard for the source of these ECMs. To overcome the several limitations related to these ECM sources, including the highly limited availability of donor tissues, cell-derived ECM offers an alternative approach for engineering tissue-specific biomaterials, such as bioinks for three-dimensional (3D) bioprinting. 3D bioprinting is a state-of-the-art biofabrication technology that addresses the global need for donor tissues and organs. In fact, there is a vast global demand for human donor corneas that are used for treating corneal blindness, often resulting from damage in the corneal stromal microstructure. Human adipose tissue is one of the most abundant tissues and easy to access, and adipose tissue-derived stem cells (hASCs) are a highly advantageous cell type for tissue engineering. Furthermore, hASCs have already been studied in clinical trials for treating corneal stromal pathologies. In this study, a corneal stroma-specific ECM was engineered without the need for donor corneas by differentiating hASCs toward corneal stromal keratocytes (hASC-CSKs). Furthermore, this ECM was utilized as a component for corneal stroma-specific bioink where hASC-CSKs were printed to produce corneal stroma structures. This cost-effective approach combined with a clinically relevant cell type provides valuable information on developing more sustainable tissue-specific solutions and advances the field of corneal tissue engineering.

Resembling mesenchymal stem cell microenvironment with growth factors loaded synthetic coral matrix for bone tissue engineering

The important factor in the design and realization of tissue engineering is the structure of three-dimensional (3D) synthetic scaffold that functions as synthetic extracellular matrix (ECM) which mimicking natural cell environment and preserve bioactive signal molecules such as growth factors (GFs). In this study, formulation of synthetic three-dimensional (3D) coral matrices was developed, characterized, and screened to obtain the most ideal formulation. Consecutively matrix ability to induce MSCs (mesenchymal stem cells) to differentiate into osteoblast both in vitro and in vivo was investigated. The potential matrix was observed for its capability in enhancing bone regeneration process within various culture conditions involving either standard culture medium or osteogenic medium, with the presence or absence of GFs cocktail in platelet rich plasma (PRP) and MSCs. Expressions of Runx, Osterix, and Osteocalcin markers were measured following the analysis on cell attachment and proliferations. Among several fabricated synthetic 3D coral matrices in various concentrations, SC-05 formulation was found preferable with the lowest degradability rate of 39.31 ± 3.55 % even after 96 h immersion in phosphate buffer saline continued by 6 h in acid solution. The release profile of PRP from the SC-05 matrix was also found preferable at 81.55 ± 1.15 %. The matrix loaded with growth factors cocktail from PRP provided ideal microenvironment for MSCs to attach, proliferate, and differentiate into osteoblast indicated by high expression level of Runx2, Osterix, and Osteocalcin. This verified that engineered microenvironment based on SCM loaded with growth factors can enhance bone tissue regeneration.

The Effect of MultilayeredElectrospun PLLA Nanofibers Coated with Human Amnion or Bladder ECM Proteins on Epithelialization and Smooth Muscle Regeneration in the Rabbit Bladder.

Nanofibrous scaffolds have attracted much attention in bladder reconstruction approaches due to their excellent mechanical properties. In addition, their biological properties can be improved by combination with biological materials. Taking into account the advantages of nanofibrous scaffolds and decellularized extracellular matrix (dECM) in tissue engineering, scaffolds of poly-L-lactic acid (PLLA) coated with decellularized human amnion membrane (hAM) or sheep bladder (SB)-derived ECM proteins are developed (amECM-coated PLLA and sbECM-coated PLLA, respectively). The bladder regenerative potential of modified electrospun PLLA scaffolds is investigated in rabbits. The presence of ECM proteins is confirmed on the nanofibers' surface. Coating the surface of the PLLA nanofibers improves cell adhesion and proliferation. Histological and immunohistochemical evaluations show that rabbits subjected to cystoplasty with a multilayered PLLA scaffold show de novo formation and maturation of the multilayered urothelial layer. However, smooth muscle bundles (myosin heavy chain [MHC] and α-smooth muscle actin [α-SMA] positive) are detected only in ECM-coated PLLA groups. All groups show no evidence of a diverticulumor fistula in the urinary bladder. These results suggest that the biofunctionalization of electrospun PLLA nanofibers with ECM proteins can be a promising option for bladder tissue engineering. Furthermore, hAM can also replace animal-sourced ECM proteins in bladder tissue regeneration approaches.

Recent advances in soluble decellularized extracellular matrix for heart tissue engineering and organ modeling.

Despite the advent of tissue engineering (TE) for the remodeling, restoring, and replacing damaged cardiovascular tissues, the progress is hindered by the optimal mechanical and chemical properties required to induce cardiac tissue-specific cellular behaviors including migration, adhesion, proliferation, and differentiation. Cardiac extracellular matrix (ECM) consists of numerous structural and functional molecules and tissue-specific cells, therefore it plays an important role in stimulating cell proliferation and differentiation, guiding cell migration, and activating regulatory signaling pathways. With the improvement and modification of cell removal methods, decellularized ECM (dECM) preserves biochemical complexity, and bio-inductive properties of the native matrix and improves the process of generating functional tissue. In this review, we first provide an overview of the latest advancements in the utilization of dECM in in vitro model systems for disease and tissue modeling, as well as drug screening. Then, we explore the role of dECM-based biomaterials in cardiovascular regenerative medicine (RM), including both invasive and non-invasive methods. In the next step, we elucidate the engineering and material considerations in the preparation of dECM-based biomaterials, namely various decellularization techniques, dECM sources, modulation, characterizations, and fabrication approaches. Finally, we discuss the limitations and future directions in fabrication of dECM-based biomaterials for cardiovascular modeling, RM, and clinical translation.

Application of Decellularized Adipose Matrix as a Bioscaffold in Different Tissue Engineering.

With the development of tissue engineering, the application of decellularized adipose matrix as scaffold material in tissue engineering has been intensively explored due to its wide source and excellent potential in tissue regeneration. Decellularized adipose matrix is a promising candidate for adipose tissue regeneration, while modification of decellularized adipose matrix scaffold can also allow it to transcend the limitations of adipose tissue source properties and applied to other tissue engineering fields, including cartilage and bone tissue engineering, neural tissue engineering, and skin tissue engineering. In this review, we summarized the development of the applications of decellularized adipose matrix in different tissue engineering and present future perspectives.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 .

Drug-Loaded Konjac Glucomannan/Metal-Organic Framework Composite Hydrogels as Antibacterial and Anti-Inflammatory Cell Scaffolds.

Bacterial infections severely threaten human health; therefore, it is important to endow the matrix for tissue engineering with antibacterial efficiency. The loading of antibacterial drugs on nanomaterials provides an efficient strategy to realize synergistic antibacterial efficiency. By depositing various metal-organic frameworks, such as UIO-66, onto konjac glucomannan (KGM), composite hydrogels (KGM/UIO-66) were created. These hydrogels were used as drug carriers, enabling the development of antibacterial hydrogels with high drug loading capacities (e.g., the maximum loading amount of pterostilbene on KGM/UIO-66 reached 0.157 mg/mg) and sustained drug release. The resulting KGM/UIO-66/pterostilbene hydrogel exhibited a three-dimensional porous structure, excellent biocompatibility, antibacterial efficiency, and anti-inflammatory activity. It effectively protected cells from bacterial attacks while ensuring cell adhesion and proliferation, demonstrating great potential as a three-dimensional substrate for biomedical applications, including tissue engineering and regenerative medicine.

Mesenchymal stem cells osteogenic differentiation by ZnO nanoparticles and polyurethane bimodal foam nanocomposites.

Mesenchymal stem cells with tissue repair capacity involve in regenerative medicine. MSCs can promote bone repair when employed with nano scaffolds/particles. Here, the MTT and Acridine Orange assay enabled the cytotoxic concentration of Zinc oxide nanoparticles and Polyurethane evaluation. Following culturing adipose tissue-derived MSCs, ADSCs' proliferation, growth, and osteogenic differentiation in the presence of PU with and without ZnO NPs is tracked by a series of biological assays, including Alkaline Phosphatase activity, Calcium deposition, alizarin red staining, RT-PCR, scanning electron microscope, and immunohistochemistry. The results showed boosted osteogenic differentiation of ADSCs in the presence of 1% PU scaffold and ZnO NPS and can thus apply as a new bone tissue engineering matrix. The expression level of Osteonectin, Osteocalcin, and Col1 increased in PU-ZnO 1% on the 7th and 14th days. There was an increase in the Runx2 gene expression on the 7th day of differentiation in PU-ZnO 1%, while it decreased on day 14th. In conclusion, Polyurethane nano scaffolds supported the MSCs' growth and rapid osteogenic differentiation. The PU-ZnO helps not only with cellular adhesion and proliferation but also with osteogenic differentiation.

Placenta Powder-Infused Thiol-Ene PEG Hydrogels as Potential Tissue Engineering Scaffolds.

Human placenta is a source of extracellular matrix for tissue engineering. In this study, placenta powder (PP), made from decellularized human placenta, was physically incorporated into synthetic poly(ethylene glycol) (PEG)-based hydrogels via UV-initiated thiol-ene coupling (TEC). The PP-incorporated PEG hydrogels (MoDPEG+) showed tunable storage moduli ranging from 1080 ± 290 to 51,400 ± 200 Pa. The addition of PP (1, 4, or 8 wt %) within the PEG hydrogels increased the storage moduli, with the 8 wt % PP hydrogels showing the highest storage moduli. PP reduced the swelling ratios compared with the pristine hydrogels (MoDPEG). All hydrogels showed good biocompatibility in vitro toward human skin cells and murine macrophages, with cell viability above 91%. Importantly, cells could adhere and proliferate on MoDPEG+ hydrogels due to the bioactive PP, while MoDPEG hydrogels were bio-inert as cells moved away from the hydrogel or were distributed in a large cluster on the hydrogel surface. To showcase their potential use in application-driven research, the MoDPEG+ hydrogels were straightforwardly (i) 3D printed using the SLA technique and (ii) produced via high-energy visible light (HEV-TEC) to populate damaged soft-tissue or bone cavities. Taking advantage of the bioactivity of PP and the tunable physicochemical properties of the synthetic PEG hydrogels, the presented MoDPEG+ hydrogels show great promise for tissue regeneration.

Biomimetic cellulose/collagen/silk fibroin as a highly interconnected 3D hybrid matrix for bone tissue engineering

The limitations of the existing graft materials in the bone reconstruction practice will be met by the porous polymeric scaffolds with osteoconductive property. In this study, microcrystalline cellulose (CEL) and collagen (COL) along with the silk fibroin (SF) protein were fabricated into a porous hybrid matrix (CEL-COL-SF). The fabricated 3D hybrid matrix possesses interconnected porous architecture which helps in the cell adhesion, proliferation, migration and minerals deposition with excellent oxygen permeability. In addition, the CEL-COL-SF hybrid matrix showed excellent biocompatibility and cell proliferation when seeded with NIH 3T3 fibroblast cells and MG-63 osteoblast like cells. The osteogenic potential of the hybrid matrix was evaluated with MG-63 cells to reveal the sequence of events related to bone regeneration. The matrix exhibited increased alkaline phosphatase expression on day 7 as an initial event of bone regeneration process and paves way for the calcification process. As a result of the alizarin red activity, the calcium deposition on day 14 increases. Biomineralization activity reveals the atomic ratio of calcium to phosphate in the hybrid matrix with 1.65, which mimics the atomic ratio of Ca/P of bone. Thus, results suggest that the hybrid matrix is a promising bone construct in bone tissue engineering.

Cartilage Injury Repair by Human Umbilical Cord Wharton's Jelly/Hydrogel Combined with Chondrocyte.

Purpose: There is still a lack of effective treatments for cartilage damage. Cartilage tissue engineering could be a promising treatment method. Human umbilical cord Wharton's jelly (HUCWJ) and hydrogels have received wide attention as a scaffold for tissue engineering. They have not been widely used in clinical studies as their effectiveness and safety are still controversial. This study systematically compared the ability of these two biological tissue engineering materials to carry chondrocytes to repair cartilage injury in vivo. Methods: Chondrocytes were cocultured with HUCWJ or hydrogel for in vivo transplantation. The treatments comprised the HUCWJ+cell, hydrogel+cell, and blank groups. A rabbit model with articular cartilage defect in the knee joint area was established. The defective knee cartilage of different rabbit groups was treated for 3 and 6 months. The efficacy of the various treatments on articular cartilage injury was evaluated by immunohistochemistry and biochemical indices. Results: We found that the HUCWJ+cell and hydrogel+cell groups promoted cartilage repair compared with the blank group, which had no repair effect. The treatment efficacy of each group at 6 months was significantly better than that at 3 months. HUCWJ showed accelerated cartilage repair ability than the hydrogel. Conclusion: This study showed that HUCWJ is useful in cartilage tissue engineering to enhance the efficacy of chondrocyte-based cartilage repair, providing new insights for regenerative medicine. Impact statement Human umbilical cord Wharton's jelly (HUCWJ) and hydrogel are the suitable extracellular matrix for cartilage tissue engineering. This study assessed the capacity of HUCWJ- and hydrogel-loaded chondrocytes to repair cartilage injury in vivo. The data demonstrate that both HUCWJ and hydrogel effectively facilitated cartilage repair, and the repair effects of HUCWJ were significantly better compared with hydrogel, therefore providing a potential candidate for clinical practice of cartilage regeneration therapy.

Thiol-ene-mediated degradable POSS-PEG/PEG hybrid hydrogels as potential cell scaffolds in tissue engineering

Tissue engineering provides therapeutic strategies for the loss or failure of human organs and tissues. As a three-dimensional biomaterial that simulates extracellular matrix (ECM) in tissue engineering, hydrogels have attracted much attention and been used as cell scaffolds. Herein, three POSS-PEG/PEG hydrogels with different solid contents were designed and developed through thiol-ene click reaction between a star-shaped cross-linker allyl-terminated poly(ethylene glycol)-functionalized polyhedral oligosiloxane (POSS-PEG-Allyl) and poly(ethylene glycol)-dithiol (SH-PEG-SH). The chemical structures, microscopic morphologies, element distribution mapping, rheological properties, swelling properties, in vitro degradation and cytocompatibility of the hydrogels were further investigated. The results showed that the hybrid hydrogels contain a large amount of water, which can create a suitable water environment for cell growth. The mechanical strength of the hybrid hydrogels is improved by introducing POSS nanoparticles to the hydrogel system, and the ester groups in the cross-linker allow the hydrogel network can be biodegrade by hydrolytic cleavage. The mechanical strength and the degradation rate can be adjusted by the solid content of the hybrid hydrogels. Besides, the hybrid hydrogel has excellent cell compatibility and porous internal structure, which provide conditions for cell growth and proliferation. Therefore, it can be considered that the hybrid hydrogel has great application potential as a cell scaffold material.

Fabrication of polycaprolactone/heparinized nano fluorohydroxyapatite scaffold for bone tissue engineering uses

In this study, some polycaprolactone (PCL)/heparinized nano fluorohydroxyapatite (H-nFHA) scaffolds were fabricated with different amounts of H-nFHA using solid-liquid phase separation and freeze-drying methods. The scaffolds were characterized using Fourier transform infrared spectroscopy, x-ray diffraction, scanning electron microscopy techniques, and compressive test. Their biological behavior also was studied using Alkaline phosphatase activity and MTT assay. The results showed that adding H-nFHA to the PCL matrix improves MG-63 cells adhesion and proliferation and they also showed that heparinizing the nFHA particles improves the mechanical properties and dispersion of the nFHA particles in the PCL matrix for bone tissue engineering uses.

Polymeric Scaffolds Used in Dental Pulp Regeneration by Tissue Engineering Approach.

Currently, the challenge in dentistry is to revitalize dental pulp by utilizing tissue engineering technology; thus, a biomaterial is needed to facilitate the process. One of the three essential elements in tissue engineering technology is a scaffold. A scaffold acts as a three-dimensional (3D) framework that provides structural and biological support and creates a good environment for cell activation, communication between cells, and inducing cell organization. Therefore, the selection of a scaffold represents a challenge in regenerative endodontics. A scaffold must be safe, biodegradable, and biocompatible, with low immunogenicity, and must be able to support cell growth. Moreover, it must be supported by adequate scaffold characteristics, which include the level of porosity, pore size, and interconnectivity; these factors ultimately play an essential role in cell behavior and tissue formation. The use of natural or synthetic polymer scaffolds with excellent mechanical properties, such as small pore size and a high surface-to-volume ratio, as a matrix in dental tissue engineering has recently received a lot of attention because it shows great potential with good biological characteristics for cell regeneration. This review describes the latest developments regarding the usage of natural or synthetic scaffold polymers that have the ideal biomaterial properties to facilitate tissue regeneration when combined with stem cells and growth factors in revitalizing dental pulp tissue. The utilization of polymer scaffolds in tissue engineering can help the pulp tissue regeneration process.

Icariin: A Promising Natural Product in Biomedicine and Tissue Engineering.

Among scaffolds used in tissue engineering, natural biomaterials such as plant-based materials show a crucial role in cellular function due to their biocompatibility and chemical indicators. Because of environmentally friendly behavior and safety, green methods are so important in designing scaffolds. A key bioactive flavonoid of the Epimedium plant, Icariin (ICRN), has a broad range of applications in improving scaffolds as a constant and non-immunogenic material, and in stimulating the cell growth, differentiation of chondrocytes as well as differentiation of embryonic stem cells towards cardiomyocytes. Moreover, fusion of ICRN into the hydrogel scaffolds or chemical crosslinking can enhance the secretion of the collagen matrix and proteoglycan in bone and cartilage tissue engineering. To scrutinize, in various types of cancer cells, ICRN plays a decisive role through increasing cytochrome c secretion, Bax/Bcl2 ratio, poly (ADP-ribose) polymerase as well as caspase stimulations. Surprisingly, ICRN can induce apoptosis, reduce viability and inhibit proliferation of cancer cells, and repress tumorigenesis as well as metastasis. Moreover, cancer cells no longer grow by halting the cell cycle at two checkpoints, G0/G1 and G2/M, through the inhibition of NF-κB by ICRN. Besides, improving nephrotoxicity occurring due to cisplatin and inhibiting multidrug resistance are the other applications of this biomaterial.

Development of porous scaffolds based on the in situ synthesis of biphasic calcium phosphate in a gelatin-polyvinyl alcohol matrix for bone tissue engineering

3D porous scaffolds are the preferred scaffold for tissue engineering applications that require good biocompatibility and mechanical properties. However, those scaffolds, based on gelatin and calcium phosphate, have been shown to be elusive due to the difficulty of reconciling excellent biological properties, long-term degradation, and desirable mechanical properties of scaffolds. Here, we designed porous scaffolds based on biphasic calcium phosphate (BCP: a mixture of hydroxyapatite (HAp) and β-tricalcium phosphate (TCP)) and polymer (gelatin and polyvinyl alcohol (PVA)) composite hydrogel using a lyophilization technique. BCP was prepared in situ in gelatin and PVA at polymer/BCP ratios equal to 0. 2, 0. 4, and 0. 6. The composition and structure of the scaffolds were investigated using a variety of techniques: XRD, FTIR, TGA-DTA, and SEM. The mechanical properties and in vitro swelling-degradation studies of the scaffolds were investigated. The results showed the formation of well-dispersed BCP in scaffolds with different HAp/TCP ratios. Scaffolds with lower content of BCP showed higher porosity and somewhat lower mechanical properties, lower diffusion of ceramic particles into fine pores and reduced pore size shrinkage compared to those with higher content of BCP. The scaffolds had good mechanical compressive strength in the range of 40–70 kPa, porosity of 10–90% and pore size of 10–310 μm. They exhibited high permeability, high swelling capacity of up to 800%, long-term swelling and degradation behavior of up to 42 days. These porous scaffolds could be potential biomaterials for damaged bones in orthopedic tissue engineering.

Криогенно-структурированный миметик внеклеточного матрикса на основе концентрированного коллагенсодержащего раствора

Viscoelastic hydrogels based on animal tissue extracts are considered promising biomimetics of the extracellular matrix (ECM) due to their proven effectiveness for stimulating the regeneration of the liver, pancreas and articular cartilage. Cryostructuring is an approach that makes it possible to give polymer scaffolds macroporosity and provide mechanical strength. preparation of a new macroporous cryogenically structured biomimetic of ECM based on a commercially available concentrated collagen-containing solution and evaluation of the possibilities of its application in tissue engineering. The target spongy collagen-containing material was obtained by sequential freezing of a concentrated collagen-containing solution, its subsequent lyophilization and chemical tanning by treatment with an alcohol solution of carbodiimide. The morphology of the cryostructured multicomponent collagen-containing material was studied using optical and scanning electron microscopy (SEM) using lanthanide contrast. The cytotoxicity of the scaffold was studied on the culture of human adipose-derived stem cells (hADSCs). Adhesion and proliferation of hADSCs on the scaffold surface were studied on the 7th day of cultivation. The compression modulus of elasticity of the obtained collagen–containing material in the swollen state in water was 35,3 ± 2,2 kPa, the total water-holding capacity of the material was 45.80 ± 0.46 ml/g of polymer, and the degree of swelling of the walls of macropores was 3.99 ± 0.31 ml/g. During SEM examination and histological staining with hematoxylin and eosin, a broad-pored structure was observed on the surface and cross-section of the disc. The pores in the upper part are larger (the average diameter is not less than ~ 30 µm) than the pores in the lower part of the sponge (the average diameter is not more than ~ 30 µm) due to the occurrence of a vertical temperature gradient. The matrix did not have cytotoxicity relative to the hADSCs. In the sample, active proliferation of hADSCs was observed on the surface of the scaffold. It was shown that the developed cryostructurates based on a concentrated collagen-containing solution had supermacroporosity and a compression modulus of elasticity of 35.3 ± 2.2 kPa. The absence of cytotoxicity and the ability to maintain adhesion and proliferation of hADSCs indicate the possibility of using cryogenically structured biomimetic of the extracellular matrix in tissue engineering and regenerative medicine.

Effects of Different Perfusing Routes through The Portal Vein, Hepatic Vein, and Biliary Duct on Whole Rat Liver Decellularization.

Organ transplantation is the last therapeutic choice for end-stage liver failure, which is limited by the lack of sufficient donors. Decellularized liver can be used as a suitable matrix for liver tissue engineering with clinical application potential. Optimizing the decellularization procedure would obtain a biological matrix with completely removed cellular components and preserved 3-dimensional structure. This study aimed to evaluate the decellularization efficacy through three anatomical routes. In this experimental study, rat liver decellularization was performed through biliary duct (BD), portal vein (PV), and hepatic vein (HV); using chemical detergents and enzymes. The decellularization efficacy was evaluated by measurement of DNA content, extracellular matrix (ECM) total proteins, and glycosaminoglycans (GAGs). ECM preservation was examined by histological and immunohistochemical (IHC) staining and scanning electron microscopy (SEM). Scaffold biocompatibility was tested by the MTT assay for HepG2 and HUVEC cell lines. Decellularization through HV and PV resulted in a transparent scaffold by complete cell removal, while the BD route produced an opaque scaffold with incomplete decellularization. H and E staining confirmed these results. Maximum DNA loss was obtained using 1% and 0.5% sodium dodecyl sulfate (SDS) in the PV and HV groups and the DNA content decreased faster in the HV group. At the final stages, the proteins excreted in the HV and PV groups were significantly less than the BD group. The GAGs level was diminished after decellularization, especially in the PV and HV groups. In the HV and PV groups the collagen amount was significantly more than the BD group. The IHC and SEM images showed that the ECM structure was preserved and cellular components were entirely removed. MTT assay showed the biocompatibility of the decellularized scaffold. The results revealed that the HV is a more suitable route for liver decellularization than the PV and BD.

Biofabrication of Poly(glycerol sebacate) Scaffolds Functionalized with a Decellularized Bone Extracellular Matrix for Bone Tissue Engineering.

The microarchitecture of bone tissue engineering (BTE) scaffolds has been shown to have a direct effect on the osteogenesis of mesenchymal stem cells (MSCs) and bone tissue regeneration. Poly(glycerol sebacate) (PGS) is a promising polymer that can be tailored to have specific mechanical properties, as well as be used to create microenvironments that are relevant in the context of BTE applications. In this study, we utilized PGS elastomer for the fabrication of a biocompatible and bioactive scaffold for BTE, with tissue-specific cues and a suitable microstructure for the osteogenic lineage commitment of MSCs. In order to achieve this, the PGS was functionalized with a decellularized bone (deB) extracellular matrix (ECM) (14% and 28% by weight) to enhance its osteoinductive potential. Two different pore sizes were fabricated (small: 100-150 μm and large: 250-355 μm) to determine a preferred pore size for in vitro osteogenesis. The decellularized bone ECM functionalization of the PGS not only improved initial cell attachment and osteogenesis but also enhanced the mechanical strength of the scaffold by up to 165 kPa. Furthermore, the constructs were also successfully tailored with an enhanced degradation rate/pH change and wettability. The highest bone-inserted small-pore scaffold had a 12% endpoint weight loss, and the pH was measured at around 7.14. The in vitro osteogenic differentiation of the MSCs in the PGS-deB blends revealed a better lineage commitment of the small-pore-sized and 28% (w/w) bone-inserted scaffolds, as evidenced by calcium quantification, ALP expression, and alizarin red staining. This study demonstrates a suitable pore size and amount of decellularized bone ECM for osteoinduction via precisely tailored PGS elastomer BTE scaffolds.