Materials For Regenerative Medicine Research Articles

Mass Spectrometry of Collagen-Containing Allogeneic Human Bone Tissue Material

The current paper highlights the active development of tissue engineering in the field of the biofabrication of living tissue analogues through 3D-bioprinting technology. The implementation of the latter is impossible without important products such as bioinks and their basic components, namely, hydrogels. In this regard, tissue engineers are searching for biomaterials to produce hydrogels with specified properties both in terms of their physical, mechanical and chemical properties and in terms of local biological effects following implantation into an organism. One of such effects is the provision of the optimal conditions for physiological reparative regeneration by the structural components that form the basis of the biomaterial. Therefore, qualitative assessment of the composition of the protein component of a biomaterial is a significant task in tissue engineering and bioprinting. It is important for predicting the behaviour of printed constructs in terms of their gradual resorption followed by tissue regeneration due to the formation of a new extracellular matrix. One of the most promising natural biomaterials with significant potential in the production of hydrogels and the bioinks based on them is the polymer collagen of allogeneic origin, which plays an important role in maintaining the structural and biological integrity of the extracellular matrix, as well as in the morphogenesis and cellular metabolism of tissues, giving them the required mechanical and biochemical properties. In tissue engineering, collagen is widely used as a basic biomaterial because of its availability, biocompatibility and facile combination with other materials. This manuscript presents the main results of a mass spectrometry analysis (proteomic assay) of the lyophilized hydrogel produced from the registered Lyoplast® bioimplant (allogeneic human bone tissue), which is promising in the field of biotechnology. Proteomic assays of the investigated lyophilized hydrogel sample showed the presence of structural proteins (six major collagen fibers of types I, II, IV, IX, XXVII, XXVIII were identified), extracellular matrix proteins, and mRNA-stabilizing proteins, which participate in the regulation of transcription, as well as inducer proteins that mediate the activation of regeneration, including the level of circadian rhythm. The research results offer a new perspective and indicate the significant potential of the lyophilized hydrogels as an effective alternative to synthetic and xenogeneic materials in regenerative medicine, particularly in the field of biotechnology, acting as a matrix and cell-containing component of bioinks for 3D bioprinting.

New Materials Based on Collagen and Taxifolin Derivatives: Production and Properties

In this work, the properties of gel materials based on collagen and derivatives of taxifolin, pentaglutarate of taxifolin, and conjugate of taxifolin with glyoxylic acid were studied. It was shown that the increase in the proportion of the polyphenols in a gel led to the decrease in the rate of degradation of the materials. The materials had no negative impact on the viability of NIH/3T3 cells. The cells attached to the surface of the materials. Moreover, it was shown that they spread to the surface of the material containing pentaglutarate of taxifolin. It was also found that fibroblast migrated throughout the materials. An increase in the proportion of conjugate of taxifolin with glyoxylic acid in a material led to a decrease in cell migration throughout the material, whereas an increase in the proportion of pentaglutarate of taxifolin in a material led to a significant increase in cell migration throughout the material. The obtained data suggest that new materials for regenerative medicine can be derived from collagen and taxifolin derivatives.

The platelet concentrates’ the hallmark in regeneration

Numerous studies have been done on the use of biocompatible materials in regenerative medicine. Platelet concentrates, also known as concentrated growth factor, platelet-rich fibrin, and platelet-rich plasma, are the result of centrifuging blood to separate out the platelets. Platelet concentrations have generated a great deal of discussion in both soft and hard tissue engineering. In fact, growth factors, fibrin matrix, and platelets are among the components of autologous platelet concentrate that are essential for the healing of wounds. Modern techniques for tissue restoration by increasing the properties of autologous platelet concentrates are the subject of current research. The usage of platelet concentrates and their role in tissue regeneration are addressed in the current study, along with a number of new advances and its biological effects.

Plasma-induced Polymerization and Grafting of Acrylic Acid on the Polypropylene Nonwoven Fabric Using Pulsed Underwater Diaphragm Electrical Discharge

Polypropylene (PP) nonwovens are used in many hygiene, healthcare and medical products due to their low cost, high chemical resistance and inertness. From an economic point of view, PP textiles would be used as an excellent support material in regenerative medicine or tissue engineering, but here surface functionalization is necessary to ensure cell adhesion and proliferation. Acrylic acid (AAc) is an excellent source of carboxylic-rich (-COOH) coatings suitable for this purpose, but their multistep preparation is time-consuming. Plasma polymerization provides an excellent solution to this demanding procedure since the process of polymerization and grafting to the substrate takes place simultaneously. Here, we propose a relatively fast and effective method for AAc plasma polymerization by using a pulsed underwater diaphragm electrical discharge operated in an aqueous solution consisting of AAc. AAc layers are successfully grafted onto PP nonwovens, which are continuously rewound through the slit where the plasma is generated. The presence of plasma polymerized AAc layer in the fibrous structure of PP nonwoven was monitored by SEM, FTIR and XPS measurements. Additionally, the improved wettability and adhesion characteristics were investigated by the critical wetting surface tension (CWST) method, the standard method of strike-through time (STT) and „tape-peel“ test. Resulting AAc modified PP nonwoven possesses hydrophilic character, enhanced adhesion and a considerable amount of -COOH groups on the surface. Although after the washing test the FTIR and XPS results indicated a lower concentration of the carboxylic groups, the CWST and STT measurements confirmed the stable hydrophilic character of the PP nonwovens surface.

Organic-inorganic composite hydrogels: compositions, properties, and applications in regenerative medicine.

Hydrogels, formed from crosslinked hydrophilic macromolecules, provide a three-dimensional microenvironment that mimics the extracellular matrix. They served as scaffold materials in regenerative medicine with an ever-growing demand. However, hydrogels composed of only organic components may not fully meet the performance and functionalization requirements for various tissue defects. Composite hydrogels, containing inorganic components, have attracted tremendous attention due to their unique compositions and properties. Rigid inorganic particles, rods, fibers, etc., can form organic-inorganic composite hydrogels through physical interaction and chemical bonding with polymer chains, which can not only adjust strength and modulus, but also act as carriers of bioactive components, enhancing the properties and biological functions of the composite hydrogels. Notably, incorporating environmental or stimulus-responsive inorganic particles imparts smartness to hydrogels, hence providing a flexible diagnostic platform for in vitro cell culture and in vivo tissue regeneration. In this review, we discuss and compare a set of materials currently used for developing organic-inorganic composite hydrogels, including the modification strategies for organic and inorganic components and their unique contributions to regenerative medicine. Specific emphasis is placed on the interactions between the organic or inorganic components and the biological functions introduced by the inorganic components. The advantages of these composite hydrogels indicate their potential to offer adaptable and intelligent therapeutic solutions for diverse tissue repair demands within the realm of regenerative medicine.

Diels-Alder Photoclick Patterning of Extracellular Matrix for Spatially Controlled Cell Behaviors.

Strategies that mimic the spatial complexity of natural tissues can provide cellular scaffolds to probe fundamental questions in cell biology and offer new materials for regenerative medicine. Here, the authors demonstrate a light-guided patterning platform that uses natural engineered extracellular matrix (ECM) proteins as a substrate to program cellular behaviors. A photocaged diene which undergoes Diels-Alder-based click chemistry upon uncaging with 365nm light is utilized. By interfacing with commercially available maleimide dienophiles, patterning of common ECM proteins (collagen, fibronectin Matrigel, laminin) with readily purchased functional small molecules and growth factors is achieved. Finally, the use of this platform to spatially control ERK activity and migration in mammalian cells is highlighted, demonstrating programmable cell behavior through patterned chemical modification of natural ECM.

Capitalization of Graphene/Chitosan Nanocomposites as Intriguing Vehicles for Targeted Anti‐Cancer Drug Delivery

AbstractThe effective combination of various polysaccharides with graphene derivatives toward the formation of nanocomposites has gained enormous interest for a number of emerging biological and biomedical applications. The intriguing properties of the individual materials are further improved upon the realization of (nano)composites, thus providing new insights and property enhancement in terms of durability, flexibility, biocompatibility, low‐toxicity, and antibacterial/antimicrobial behavior. Therefore, novel (nano)composite agents are prepared and investigated to serve as ideal carriers or scaffold materials in regenerative medicine, biosensing, disease diagnosis and treatment, drug delivery, as well as stem cell and tissue engineering applications. This topical review summarizes the most recent studies published during the last quinquennium (2018–2022), on the development of anticancer drug delivery systems (DDSs) based on graphene/chitosan (CS) nanocomposites. The followed synthetic routes and the integrated properties of the composite materials are analyzed, discussing the impact of their utilization in the field of drug delivery for the treatment of various cancer types. The prospects and future research trends in the field are also discussed.

Self-Assembled Peptide Hydrogels in Regenerative Medicine.

Regenerative medicine is a complex discipline that is becoming a hot research topic. Skin, bone, and nerve regeneration dominate current treatments in regenerative medicine. A new type of drug is urgently needed for their treatment due to their high vulnerability to damage and weak self-repairing ability. A self-assembled peptide hydrogel is a good scaffolding material in regenerative medicine because it is similar to the cytoplasmic matrix environment; it promotes cell adhesion, migration, proliferation, and division; and its degradation products are natural and harmless proteins. However, fewer studies have examined the specific mechanisms of self-assembled peptide hydrogels in promoting tissue regeneration. This review summarizes the applications and mechanisms of self-assembled short peptide and peptide hydrogels in skin, bone, and neural healing to improve their applications in tissue healing and regeneration.

3D Printing, Histological, and Radiological Analysis of Nanosilicate-Polysaccharide Composite Hydrogel as a Tissue-Equivalent Material for Complex Biological Bone Phantom.

Nanosilicate-polysaccharide composite hydrogels are a well-studied class of materials in regenerative medicine that combine good 3D printability, staining, and biological properties, making them an excellent candidate material for complex bone scaffolds. The aim of this study was to develop a hydrogel suitable for 3D printing that has biological and radiological properties similar to those of the natural bone and to develop protocols for their histological and radiological analysis. We synthesized a hydrogel based on alginate, methylcellulose, and laponite, then 3D printed it into a series of complex bioscaffolds. The scaffolds were scanned with CT and CBCT scanners and exported as DICOM datasets, then cut into histological slides and stained using standard histological protocols. From the DICOM datasets, the average value of the voxels in Hounsfield Units (HU) was calculated and compared with natural trabecular bone. In the histological sections, we tested the effect of standard histological stains on the hydrogel matrix in the context of future cytological and histological analysis. The results confirmed that an alginate/methylcellulose/laponite-based composite hydrogel can be used for 3D printing of complex high fidelity three-dimensional scaffolds. This opens an avenue for the development of dynamic biological physical phantoms for bone tissue engineering and the development of new CT-based imaging algorithms for the needs of radiology and radiation therapy.

Zeolitic imidazolate frameworks: From bactericidal properties to tissue regeneration.

Zeolitic imidazolate frameworks (ZIFs), as a very well-known subset of metal-organic frameworks (MOFs), have attracted considerable attention in biomedicine due to their unique structural features such as tunable pore size, high surface area, high thermal stability, biodegradability, and biocompatibility. Moreover, it is possible to load a wide variety of therapeutic agents, drugs, and biomolecules into ZIF structures during the fabrication process owing to the ZIFs' porous structure and concise synthesis methods under mild conditions. This review focuses on the most recent advances in the bioinspiration of ZIFs and ZIF-integrated nanocomposites in boosting antibacterial efficiencies and regenerative medicine capabilities. The first part summarizes the various synthesis routes and physicochemical properties of ZIFs, including size, morphology, surface, and pore size. The recent advancements in the antibacterial aspects of using ZIFs and ZIF-integrated nanocomposites as carriers for antibacterial agents and drug cargo are elaborated. Moreover, the antibacterial mechanisms based on the factors affecting the antibacterial properties of ZIFs such as oxidative stress, internal and external triggers, the effect of metal ions, and their associated combined therapies, are discussed. The recent trends of ZIFs and their composites in tissue regeneration, especially bone regeneration and wound healing, are also reviewed with in-depth perspectives. Finally, the biological safety aspects of ZIFs, the latest reports about their toxicity, and the future prospects of these materials in regenerative medicine have been discussed.

Polymers and Bioactive Compounds with a Macrophage Modulation Effect for the Rational Design of Hydrogels for Skin Regeneration.

The development of biomaterial platforms for dispensing reagents of interest such as antioxidants, growth factors or antibiotics based on functional hydrogels represents a biotechnological solution for many challenges that the biomedicine field is facing. In this context, in situ dosing of therapeutic components for dermatological injuries such as diabetic foot ulcers is a relatively novel strategy to improve the wound healing process. Hydrogels have shown more comfort for the treatment of wounds due to their smooth surface and moisture, as well as their structural affinity with tissues in comparison to hyperbaric oxygen therapy, ultrasound, and electromagnetic therapies, negative pressure wound therapy or skin grafts. Macrophages, one of the most important cells of the innate immune system, have been described as the key not only in relation to the host immune defense, but also in the progress of wound healing. Macrophage dysfunction in chronic wounds of diabetic patients leads to a perpetuating inflammatory environment and impairs tissue repair. Modulating the macrophage phenotype from pro-inflammatory (M1) to anti-inflammatory (M2) could be a strategy for helping to improve chronic wound healing. In this regard, a new paradigm is found in the development of advanced biomaterials capable of inducing in situ macrophage polarization to offer an approach to wound care. Such an approach opens a new direction for the development of multifunctional materials in regenerative medicine. This paper surveys emerging hydrogel materials and bioactive compounds being investigated to induce the immunomodulation of macrophages. We propose four potential functional biomaterials for wound healing applications based on novel biomaterial/bioactive compound combination that are expected to show synergistic beneficial outcomes for the local differentiation of macrophages (M1-M2) as a therapeutic strategy for chronic wound healing improvement.

Application of hydrogel-loaded stem cell exosomes in the field of tissue regeneration

In recent years, mesenchymal stem cell (MSCs)-derived exosomes have attracted much attention in the field of tissue regeneration. Mesenchymal stem cell-derived exosomes are signaling molecules for communication among cells. They are characterized by natural targeting and low immunogenicity, and are mostly absorbed by cells through the paracrine pathway of mesenchymal stem cells. Moreover, they participate in the regulation and promotion of cell or tissue regeneration. As a scaffold material in regenerative medicine, hydrogel has good biocompatibility and degradability. Combining the two compounds can not only improve the retention time of exosomes at the lesion site, but also improve the dose of exosomes reaching the lesion site by in situ injection, and the therapeutic effect in the lesion area is significant and continuous. This paper summarizes the research results of the interaction of exocrine and hydrogel composite materials to promote tissue repair and regeneration, in order to facilitate research in the field of tissue regeneration in the future.

Interdisciplinary approaches to brain organoid biology

Embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs) have been widely used as materials for regenerative medicine and for modeling development and disease because of their pluripotency to differentiate into all cell types of the body. Recently, organoid research has attracted considerable attention as a constructive approach to reconstitute various tissues from ESCs or iPSCs in three-dimensional culture in vitro. Organoids can provide sophisticated in vitro models because of their ability to partially recapitulate different cell types of living tissues and their functions. However, given their complexity, conventional analyses of stem cell biology are insufficient for evaluating organoid performance, limiting basic research and clinical translation. In recent years, elucidating diverse and complex biological phenomena by integrating stem cell biology with other research fields has become feasible. In this review, we focus on brain organoids with some representative examples of interdisciplinary research using machine learning, genetic and viral engineering, and optical imaging, as well as findings obtained from such research. Furthermore, we will discuss the potential applications and future perspectives of interdisciplinary research in organoid biology.

Oxygen-releasing biomaterials for regenerative medicine.

Oxygen is critical to the survival, function and fate of mammalian cells. Oxygen tension controls cellular behavior through metabolic programming, which in turn controls tissue regeneration. A variety of biomaterials with oxygen-releasing capabilities have been developed to provide oxygen supply to ensure cell survival and differentiation for therapeutic efficacy, and to prevent hypoxia-induced tissue damage and cell death. However, controlling the oxygen release with spatial and temporal accuracy is still technically challenging. In this review, we provide a comprehensive overview of organic and inorganic materials available as oxygen sources, including hemoglobin-based oxygen carriers (HBOCs), perfluorocarbons (PFCs), photosynthetic organisms, solid and liquid peroxides, and some of the latest materials such as metal-organic frameworks (MOFs). Additionally, we introduce the corresponding carrier materials and the oxygen production methods and present state-of-the-art applications and breakthroughs of oxygen-releasing materials. Furthermore, we discuss the current challenges and the future perspectives in the field. After reviewing the recent progress and the future perspectives of oxygen-releasing materials, we predict that smart material systems that combine precise detection of oxygenation and adaptive control of oxygen delivery will be the future trend for oxygen-releasing materials in regenerative medicine.

The Effect of Cerastoderma lamarcki and Rice Bran Extract on Wharton's Jelly-Derived Mesenchymal Stem Cells Differentiation

Background & Objective: Nowadays, the use of natural materials in regenerative medicine is very important, especially using substances with calcium carbonate structure due to their similarity to the bone structure. In this study, the effect of Cerastoderma lamarcki shell and rice bran extract on stem cell proliferation and differentiation has been investigated.
 Materials & Methods: First, crastoderma shells were collected and cut into small pieces. Its compounds were analyzed by X-ray diffraction. Finally, the structural features of shells were investigated by SEM. Stem cells were extracted and cultured from the umbilical cord of Wharton's jelly. After cells seeding on the scaffold, cell survival was studied by MTT. Adhesion, morphology, and diffusion of cells on the shells were also examined by SEM. Cells were stimulated by osteogenic medium and osteoblastic differentiation by alkaline phosphatase activity was studied. Rice bran ethanolic extract was used. Cell survival was studied by MTT technique and osteogenic differentiation was studied by Alizarin Red staining.
 Results: MTT studies showed appropriate adhesion of cells on the scaffold and SEM studies also showed successful binding and their appropriate morphology on the scaffold. Alkaline phosphatase studies showed that osteogenic differentiation of cells on shells is significant. In another part of this study, we studied the survival and osteogenic differentiation of these cells in treatment with ethanolic extract of rice bran. MTT studies showed a dose-dependent decrease in cell survival in the presence of the extract. Alizarin staining also showed the differentiation potential of this substance.
 Conclusion: The results showed the appropriate potential of these two natural substances in bone differentiation. However, further studies are needed to prove their effects.

Effects of therapeutic doses of heparin on MSC functional activity in modeling the mechanisms of osteointegration under in vitro cultivation

The use of artificial materials in regenerative medicine is accompanied by the development of an inflammatory response and the initiation of blood clotting due to the contact of the implant with the soft tissues of the body. All this leads to the formation of thrombosis of the major and main arteries and the development of serious complications. To prevent the development of postoperative pathological conditions caused by hypercoagulable syndrome, classical therapeutic strategies with anticoagulants (mainly heparin) are used. However, the described treatment tactics lead to an interruption of the migration and adhesion processes of mesenchymal stem cells (MSC), which negatively affects the callus formation and the processes of osseointegration of the implant. The aim of this study was to investigate the effect of a suspension of HA nanoparticles in the presence of heparin in a gradient of therapeutic concentrations on migratory and proliferative activity of MSCs in human adipose tissue under in vitro cultivation conditions. Methods. To evaluate the migration and proliferation potential of MSC in the presence of HA nanosuspension and/or heparin, an electrode system for continuous observation — xCELLigence ® RTCA DP was used. Results. A significant decrease in the migratory activity and proliferative potential of MSC was observed under the conditions of their co-cultivation with HA nanosuspension in the presence/absence of heparin (0.5–1 IU/ml). onclusion. The results of the study may serve as a prerequisite for the development of new therapeutic approaches for the use of heparin in surgical patients at high risk of postoperative thrombosis after osteosynthesis.

Long-term culture of rat hepatocytes using human amniotic membrane as a culture substrate.

Amniotic membrane is attracting attention as a new material for regenerative medicine. We herein report that the culture of primary rat hepatocytes on human amniotic membrane maintained their morphology and their production of albumin for at least two months. Human amniotic membrane was collected during planned cesarean section and kept frozen until usage. Primary rat hepatocytes were plated on human amniotic membrane. Hepatocytes accumulated as colonies on amniotic membrane, and their rat albumin level was maintained for two months. Their three-dimensional structure on extracellular matrix, which is abundant in amniotic membranes might influence the maintenance of the hepatocyte-specific function.

Manufacturing of Human Tissues as off-the-Shelf Grafts Programmed to Induce Regeneration.

Design criteria for tissue-engineered materials in regenerative medicine include robust biological effectiveness, off-the-shelf availability, and scalable manufacturing under standardized conditions. For bone repair, existing strategies rely on primary autologous cells, associated with unpredictable performance, limited availability and complex logistic. Here, a conceptual shift based on the manufacturing of devitalized human hypertrophic cartilage (HyC), as cell-free material inducing bone formation by recapitulating the developmental process of endochondral ossification, is reported. The strategy relies on a customized human mesenchymal line expressing bone morphogenetic protein-2 (BMP-2), critically required for robust chondrogenesis and concomitant extracellular matrix (ECM) enrichment. Following apoptosis-driven devitalization, lyophilization, and storage, the resulting off-the-shelf cartilage tissue exhibits unprecedented osteoinductive properties, unmatched by synthetic delivery of BMP-2 or by living engineered grafts. Scalability and pre-clinical efficacy are demonstrated by bioreactor-based production and subsequent orthotopic assessment. The findings exemplify the broader paradigm of programming human cell lines as biological factory units to engineer customized ECMs, designed to activate specific regenerative processes.

The balanced microenvironment regulated by the degradants of appropriate PLGA scaffolds and chitosan conduit promotes peripheral nerve regeneration.

Tissue-engineered nerve grafts (TENGs) are the most promising way for repairing long-distance peripheral nerve defects. Chitosan and poly (lactic-co-glycolic acid) (PLGA) scaffolds are considered as the promising materials in the pharmaceutical and biomedical fields especially in the field of tissue engineering. To further clarify the effects of a chitosan conduit inserted with various quantity of poly (lactic-co-glycolic acid) (PLGA) scaffolds, and their degrades on the peripheral nerve regeneration, the chitosan nerve conduit inserted with different amounts of PLGA scaffolds were used to repair rat sciatic nerve defects. The peripheral nerve regeneration at the different time points was dynamically and comprehensively evaluated. Moreover, the influence of different amounts of PLGA scaffolds on the regeneration microenvironment including inflammatory response and cell state were also revealed. The modest abundance of PLGA is more instrumental to the success of nerve regeneration, which is demonstrated in terms of the structure of the regenerated nerve, reinnervation of the target muscle, nerve impulse conduction, and overall function. The PLGA scaffolds aid the migration and maturation of Schwann cells. Furthermore, the PLGA and chitosan degradation products in a correct ratio neutralize, reducing the inflammatory response and enhancing the regeneration microenvironment. The balanced microenvironment regulated by the degradants of appropriate PLGA scaffolds and chitosan conduit promotes peripheral nerve regeneration. The findings represent a further step towards programming TENGs construction, applying polyester materials in regenerative medicine, and understanding the neural regeneration microenvironment.

Involvement of somatic stem cells in encapsulation of foreign–body reaction in canine subcutaneous Biotube tissue formation

Generally, the thickness of tubular tissues formed from silicone rods through encapsulation of the foreign-body reaction is less than approximately 0.2mm. On the other hand, it is unclear how hollow cylindrical molds can provide thick tubular tissues, known as Biotubes, with a thickness exceeding 1mm, during in-body tissue architecture (iBTA) using encapsulation. In this study, histological and structural analyses were performed to understand the reason for the formation of thick mold-based Biotubes. Molds were assembled with a gap between a silicone rod and a stainless-steel cylinder and were embedded into the dorsal subcutaneous pouches of beagles for 2 or 4 weeks. Thick Biotubes were obtained from the harvested mold. The histological analysis showed that the lumen side of the thick Biotubes consisted primarily of type I collagen fibers and α-smooth muscle actin-positive cells, similar to the original rod-based thin Biotubes formed only from silicone rods. Interestingly, the outer region of the thick Biotubes was an immature connective tissue consisting of type III collagen, including primitive somatic stem cells expressing CD90 and SSEA4. These stem cells may have contributed to the formation of the thick-walled Biotubes by differentiating into other cell types and through growth factor production. Because of the potential tissue-repair ability of these stem cells, iBTA could be useful for elucidating the regeneration process, remodeling the physiology/pathology of tissue defects/damage, and cell acquisition. This technology can provide autologous stem cells without invitro cell culture. Moreover, thick-walled Biotubes may be useful as an alternative stem cell-containing material in regenerative medicine.