Potential Applications In Tissue Regeneration Research Articles

Zeolitic imidazolate framework-8: a versatile nanoplatform for tissue regeneration.

Extensive research on zeolitic imidazolate framework (ZIF-8) and its derivatives has highlighted their unique properties in nanomedicine. ZIF-8 exhibits advantages such as pH-responsive dissolution, easy surface functionalization, and efficient drug loading, making it an ideal nanosystem for intelligent drug delivery and phototherapy. These characteristics have sparked significant interest in its potential applications in tissue regeneration, particularly in bone, skin, and nerve regeneration. This review provides a comprehensive assessment of ZIF-8's feasibility in tissue engineering, encompassing material synthesis, performance testing, and the development of multifunctional nanosystems. Furthermore, the latest advancements in the field, as well as potential limitations and future prospects, are discussed. Overall, this review emphasizes the latest developments in ZIF-8 in tissue engineering and highlights the potential of its multifunctional nanoplatforms for effective complex tissue repair.

Evaluation of bone marrow-derived mesenchymal stem cells with eggshell membrane for full-thickness wound healing in a rabbit model.

Biomaterials capable of managing wounds should have essential features like providing a natural microenvironment for wound healing and as support material for stimulating tissue growth. Eggshell membrane (ESM) is a highly produced global waste due to increased egg consumption. The unique and fascinating properties of ESM allow their potential application in tissue regeneration. The wound healing capacity of bone marrow-derived mesenchymal stem cells (BM-MSCs), ESM, and their combination in rabbits with full-thickness skin defect (2 × 2cm2) was evaluated. Twenty-five clinically healthy New Zealand White rabbits were divided into five groups of five animals each, with group A receiving no treatment (control group), group B receiving only fibrin glue (FG), group C receiving FG and ESM as a dressing, group D receiving FG and BM-MSCs, and group E receiving a combination of FG, ESM, and BM-MSCs. Wound healing was assessed using clinical, macroscopical, photographic, histological, histochemical, hematological, and biochemical analysis. Macroscopic examination of wounds revealed that healing was exceptional in group E, followed by groups D and C, compared to the control group. Histopathological findings revealed improved quality and a faster rate of healing in group E compared to groups A and B. In addition, healing in group B treated with topical FG alone was nearly identical to that in control group A. However, groups C and D showed improved and faster recovery than control groups A and B. The macroscopic, photographic, histological, and histochemical evaluations revealed that the combined use of BM-MSCs, ESM, and FG had superior and faster healing than the other groups.

Immune evaluation of granulocyte-macrophage colony stimulating factor loaded hierarchically 3D nanofiber scaffolds in a humanized mice model.

Background: Immune evaluation of biomaterials for tissue regeneration is a critical preclinical evaluation. The current evaluation criterion (ISO 10993-1 or GB/T 16886) uses rodents to perform the immune evaluation. However, the immune system of rodents is different from humans, the obtained results may not be reliable, which could lead directly to the failure of clinical trials. Granulocyte-macrophage colony-stimulating factor (GM-CSF) shows a great potential application in tissue regeneration by regulating local immune responses. The presented work combines the advantages of GM-CSF (immunoregulation) and hierarchically 3D nanofiber scaffolds (tissue regeneration). Methods: Firstly, we fabricated GM-CSF loaded 3D radially aligned nanofiber scaffolds, and then subcutaneous implantation was performed in humanized mice. The whole scaffold and surrounding tissue were harvested at each indicated time point. Finally, the cell infiltration and local immune responses were detected by histological observations, including H&E and Masson staining and immunochemistry. Results: We found significant cell migration and extracellular matrix deposition within the 3D radially aligned nanofiber scaffold after subcutaneous implantation. The locally released GM-CSF could accelerate the expression of human dendritic cells (CD11c) only 3days after subcutaneous implantation. Moreover, higher expression of human cytotoxic T cells (CD3+/CD8+), M1 macrophages (CD68/CCR7) was detected within GM-CSF loaded radially aligned nanofiber scaffolds and their surrounding tissues. Conclusions: The 3D radially aligned scaffold can accelerate cell migration from surrounding tissues to regenerate the wound area. And the locally released GM-CSF enhances dendritic cell recruitment and activation of cytotoxic T cells and M1 macrophages. Taken together, the GM-CSF loaded 3D radially aligned nanofiber scaffolds have a promising potential for achieving tissue regeneration.

Effect of Electrospun PLGA/Collagen Scaffolds on Cell Adhesion, Viability, and Collagen Release: Potential Applications in Tissue Engineering

The development of scaffolding obtained by electrospinning is widely used in tissue engineering due to porous and fibrous structures that can mimic the extracellular matrix. In this study, poly (lactic-co-glycolic acid) (PLGA)/collagen fibers were fabricated by electrospinning method and then evaluated in the cell adhesion and viability of human cervical carcinoma HeLa and NIH-3T3 fibroblast for potential application in tissue regeneration. Additionally, collagen release was assessed in NIH-3T3 fibroblasts. The fibrillar morphology of PLGA/collagen fibers was verified by scanning electron microscopy. The fiber diameter decreased in the fibers (PLGA/collagen) up to 0.6 µm. FT-IR spectroscopy and thermal analysis confirmed that both the electrospinning process and the blend with PLGA give structural stability to collagen. Incorporating collagen in the PLGA matrix promotes an increase in the material's rigidity, showing an increase in the elastic modulus (38%) and tensile strength (70%) compared to pure PLGA. PLGA and PLGA/collagen fibers were found to provide a suitable environment for the adhesion and growth of HeLa and NIH-3T3 cell lines as well as stimulate collagen release. We conclude that these scaffolds could be very effective as biocompatible materials for extracellular matrix regeneration, suggesting their potential applications in tissue bioengineering.

52 - Injectable BioActive Glass for Potential Application in Tissue Regeneration

52 - Injectable BioActive Glass for Potential Application in Tissue Regeneration

Elastic Fibre Proteins in Elastogenesis and Wound Healing.

As essential components of our connective tissues, elastic fibres give tissues such as major blood vessels, skin and the lungs their elasticity. Their formation is complex and co-ordinately regulated by multiple factors. In this review, we describe key players in elastogenesis: fibrillin-1, tropoelastin, latent TGFβ binding protein-4, and fibulin-4 and -5. We summarise their roles in elastogenesis, discuss the effect of their mutations on relevant diseases, and describe their interactions involved in forming the elastic fibre network. Moreover, we look into their roles in wound repair for a better understanding of their potential application in tissue regeneration.

Graphene oxide-cellulose nanocomposite accelerates skin wound healing

The usage of materials with the potential to accelerate wound healing is a great benefit for patients and health care systems. This study evaluated the impact of using graphene oxide (GO)–cellulose nanocomposite on skin wound healing via in vitro and in vivo investigations. The nanomaterial was synthesized and characterized. Cytocompatibility performance of the GO-cellulose was investigated through in vitro testing based on MTT and live/dead assays by EA.hy926 human endothelial cells (ECs). Additionally, the effect of GO-cellulose on induced wound scratch model using EA.hy926 ECs was investigated. Finally, the therapeutic effect of GO-cellulose was evaluated in vivo after the creation of two full-thickness wounds in the dorsum of rats (8 mm diameter). These wounds were randomly placed into two groups, the control group (10 wounds) and the GO-cellulose group (10 wounds), and monitored for gross and histopathological changes at 7 and 21 days after wound induction. MTT and Live/Dead assays showed excellent GO-cellulose cytocompatibility, whereas no difference in ECs viability was observed after culturing using conditioned media. GO-cellulose nanocomposite enhanced cell migration in the in vitro wound scratch assay. As compared to the control group, the GO-cellulose nanocomposite group's wound healing process was promoted in the in vivo rat skin wounds. Interestingly, wound re-epithelization and neovascularization were significantly accelerated in the GO-cellulose-treated rats. Furthermore, thick granulation tissue formation and intense collagen deposition were found in the GO-cellulose group. These findings showed that GO-cellulose has a promoting effect on skin wound healing, suggesting its promising and potential application in tissue regeneration.

Surface nanostructuring of bioresorbable implants to induce osteogenic differentiation of human mesenchymal stromal cells

Surface nanostructuring of bioresorbable polymers is a promising solution for tissue regeneration therapies, as such nanostructured implants non-toxically degrade after producing localized and prolonged stimuli. In this work, a process chain for the fabrication of bioresorbable polymer implants was developed and validated. The implants present surface arrays of nanopillars whose main design parameters were optimized to induce the osteogenic differentiation of human stem cells. In vitro and in vivo cell experiments provided evidence for the potential application in tissue regeneration and revealed that nanopillars' diameter, height, and spacing need to be independently optimized to effectively promote osteogenic differentiation.

SYNTHESIS AND CHARACTERIZATION OF COMPOSITES BASED ON HYDROXYAPATITE NANOPARTICLES AND CHITOSAN EXTRACTED FROM SHELLS OF THE FRESHWATER CRAB Potamon algeriense

Nanocrystalline hydroxyapatite (n-HAp), which has low crystallinity, has attracted great attention due to its similarity to the inorganic part of human bone. Therefore, many studies have focused on creating new formulations combining n-HAp with some biopolymers, such as chitosan, in order to imitate biological bone tissue. The importance of chitosan and its derivatives in biomedical applications has grown significantly in the last three decades due to its biodegradability and renewable source. Besides, chitosan and its derivatives present excellent biocompatibility and biofunctionality, which make them promising materials in bone tissue engineering. In the present study, the chitosan was, first, extracted from the shell of the freshwater crab species Potamon algeriense following demineralization, deproteinization, decolouration (raw chitin) and deacetylation (chitosan) steps. Then, a novel composite based on n-HAp and extracted chitosan (CTS) with varying chitosan contents, from 5% to 20% (w/w), was synthesized and characterized for potential application in tissue regeneration. The obtained composites were characterized using X-ray diffraction, Fourier transform infrared spectroscopy and thermogravimetric analysis. The precipitated n-HAp/CTS nanocomposites similar to natural bone are promising composites for bone tissue engineering applications.

3D printing and morphological characterisation of polymeric composite scaffolds

3D-printing is an efficient method of designing customised structures and producing synthetic bone grafts appropriate for bone implants. This research aimed to manufacture a new multi-functionalised 3D-printed poly(lactic acid)/carbonated hydroxyapatite (PLA/cHA) scaffolds with mass proportions of 100/0, 95/5 and 90/10 in a bid to verify their potential application in tissue regeneration. The filaments of these hybrid materials were obtained by extrusion technique and subsequently used to manufacture the 3D-printed scaffolds, using a fused deposition modelling (FDM) technique. The scaffolds were characterised based on their thermal properties, microstructure and geometry by differential scanning calorimetry (DSC), scanning electron microscopy (SEM) and energy dispersive x-ray spectroscopy (EDS), respectively, in addition to determination of their apparent porosities. The degradation of the scaffolds and the liberation of degradation products were evaluated in in vitro for different days under simulated physiological conditions. New microanalyses of mechanical behaviour of the materials: tensile and compression stresses, density, frequency analysis and optimisation with DSC were performed. While, evaluation of the surface luminance structure and the profile structure of the nanostructured PLA composite materials was done by SEM, in 3D printed form. The filter profile of cross-sectional view of the specimen was extracted and evaluated with Firestone curve of the Gaussian filter; checking the roughness and waviness profile of the structure. It was observed that the thermal properties of the composites were not affected by the manufacturing process. The microstructural analysis showed the effective incorporation of the ceramic filler in the polymer matrix as well as an acceptable PLA/cHA interaction. The degradation tests showed the presence of calcium and phosphorus in the studied medium, confirming their liberation from the composites during the incubation periods.

Highly-defined bioprinting of long-term vascularized scaffolds with Bio-Trap: Complex geometry functionalization and process parameters with computer aided tissue engineering

Three-dimensional bioprinting, thanks to its great versatility, flexibility, perfect reproducibility and high speed, has recently emerged as a promising technology, especially in biological applications, making possible its use in different fields. In fact, synthetic organ manufacturing using natural derived polymers, with mechanical micro-extrusion technology, demonstrated its potential applications in tissue regeneration and vascular reconstruction but processes need to better control high resolution, degradation time and contamination. Here we propose a low cost liquid frozen deposition manufacturing 3D bioprinter with a smart and middle-ware technology, using customized algorithms, in order to support processes for tissue-engineering. We described 46 geometrical parameters in a ultra-defined architecture scaffolds that conserved original characteristics for more than 23 months after rehydration, and evaluated the mechanical characteristics, the surface micro-morphology and the related cell viability. Moreover, we demonstrated that the cells can be entrapped into Bio-Trap in the rehydrated scaffold thickness and can be maintained alive for 3 weeks. With these smart-technologies, it is possible to obtain a first evaluation of different process parameters and scaffold architecture for the fabrication of long-term organoid controlling the full cycle of scaffold fabrication from the biomaterial selection to the final 3D bio-architecture. Statement of significance – MaterialiaThis study has the aim to standardize the comparison and the analysis of the different scaffold's functionalized structure. In fact, the high number of possible functionalizations of dedicated biological structure, needs a structured data scheduling. Thus, this study shows a new method for the implementation of Computer Aided Tissue Engineering (CATE) using 3D bio-printing and smart technology with the aim to develop vertical channels, for the vascularization of the scaffold, and Bio-Traps able to entrap the cells within scaffold's height. This innovative technique, thanks to its flexibility, can support the personalization of high-defined scaffold geometries for in vitro research activities.

Magnetic Nanomaterials for Advanced Regenerative Medicine: The Promise and Challenges.

The recent emergence of numerous nanotechnologies is expected to facilitate the development of regenerative medicine, which is a tissue regeneration technique based on the replacement/repair of diseased tissue or organs to restore the function of lost, damaged, and aging cells in the human body. In particular, the unique magnetic properties and specific dimensions of magnetic nanomaterials make them promising innovative components capable of significantly advancing the field of tissue regeneration. Their potential applications in tissue regeneration are the focus here, beginning with the fundamentals of magnetic nanomaterials. How nanomaterials-both those that are intrinsically magnetic and those that respond to an externally applied magnetic field-can enhance the efficiency of tissue regeneration is also described. Applications including magnetically controlled cargo delivery and release, real-time visualization and tracking of transplanted cells, magnetic regulation of cell proliferation/differentiation, and magnetic activation of targeted ion channels and signal pathways involved in regeneration are highlighted, and comments on the perspectives and challenges in magnetic nanomaterial-based tissue regeneration are given.

Comparative cytocompatibility of multiple candidate cell types to photoencapsulation in PEGNB/PEGDA macroscale or microscale hydrogels

The encapsulation of live cells into photopolymerized hydrogel scaffolds has the potential to augment or repair tissue defects, establish versatile regenerative medicine strategies, and be developed as well-defined, yet tunable microenvironments to study fundamental cellular behavior. However, hydrogel fabrication limitations constrain most studies to macroscale hydrogel scaffolds encapsulating millions of cells. These macroscale materials possess regions of heterogeneous photopolymerization conditions and are therefore poor platforms to identify the response of individual cells to encapsulation. Recently, microfluidic droplet-based hydrogel miniaturization and cell encapsulation offers high-throughput, reproducible, and continuous fabrication. Reports of post-encapsulation cell viability, however, vary widely among specific techniques. Furthermore, different cell types often exhibit different level of tolerance to photoencapsulation-induced toxicity. Accordingly, we evaluate the cellular tolerance of various encapsulation techniques and photopolymerization parameters for four mammalian cell types, with potential applications in tissue regeneration, using polyethylene glycol diacrylate or polyethylene glycol norbornene (PEGNB) hydrogels on micro- and macro-length scales. We found PEGNB provides excellent cellular tolerance and supports long-term cell survival by mitigating the deleterious effects of acrylate photopolymerization, which are exacerbated at diminishing volumes. PEGNB, therefore, is an excellent candidate for hydrogel miniaturization. PEGNB hydrogel properties, however, were found to have variable effects on encapsulating different cell candidates. This study could provide guidance for cell encapsulation practices in tissue engineering and regenerative medicine research.

Ultrasonicated graphene oxide enhances bone and skin wound regeneration

In the present study, we investigated the applications of ultrasonicated graphene oxide (UGO) for bone regeneration and skin wound healing. Ultrasonication of a GO suspension increased the dispersion and stability (by increasing the zeta potential) of the GO suspension. UGO has fewer oxygen-containing groups but still displays excellent water dispersion. The UGO supension showed high biocompatibility for human fetal osteoblast (hFOB cells), human endothelial cells (EA.hy 926 cells), and mouse embryonic fibroblasts. Importantly, UGO could support cell attachment and proliferation, in addition to promoting the osteogenesis of seeded cells and the promotion of new bone formation. In addition, a 1% UGO supension enhanced cell migration in an in vitro skin scratch assay and promoted wound closure in an in vivo rat excisional skin defect model. These results showed that UGO offers a good environment for cells involved in bone and skin healing, suggesting its potential application in tissue regeneration.

Tissue-specific extracellular matrix promotes myogenic differentiation of human muscle progenitor cells on gelatin and heparin conjugated alginate hydrogels.

Alginate based biomaterials are commonly used in tissue engineering and regenerative medicine field, however, the inefficient sequestration of growth factors restricted its utilization. In this study, a novel alginate based substrates was produced covalently modified with gelatin and heparin, in order to capture more effective cytokines and proteins in the culture milieu, keep homeostasis for cell survival and tissue regeneration with growth factor sequestration and long-term release capacities. Combining with skeletal muscle derived ECM, the modified Alginate-Gelatin-Heparin gel could most effectively mimic the tissue specific microenvironment to support skeletal muscle progenitor cells proliferation, differentiation and myotube formation. Additionally, the economical and practical features will make it more promising in high-throughput application for regenerative medicine research.

Adhesión y proliferación de las células troncales mesenquimalesde médula ósea en andamios fibrilares de poli (ácido L-láctico) (PLA)

Fiber scaffolds have received increasing interest as promising biomaterials for potential application in the field of tissue regeneration. In this sense, we optimized the parameters for the synthesis of different concentrations (6, 7, and 10 %) of poly-lactic acid (PLA) scaffolds by air jet spinning technology (AJS). The PLA scaffolds were characterized by Scanning Electron Microscopy (SEM) and Fourier Transform Infrared Spectroscopy (FTIR) analysis. Our results by SEM micrographs showed that scaffolds have a fibrilar morphology with nanoscale diameter of fibers. Biocompatibility assay was observed through an in vitro experiment based on cell attachment, MTT and cell-material interaction assay when culturing bone marrow-derived mesenchymal stem cells onto the PLA spun membrane scaffolds. Our data indicate that fiber membrane of PLA scaffold increase the cellular response, are not cytotoxic when compared to thin films of PLA. Thus; the proposed synthesis method has potential for easy processing of spun fibrilar scaffolds with good biocompatibility and could be a promising economical biomaterial with future potential applications in tissue regeneration.

The effect of PEGylated hollow gold nanoparticles on stem cell migration: potential application in tissue regeneration.

Mesenchymal stem cells (MSCs) not only can be differentiated into different cell types but also have tropism towards injured or inflamed tissues serving as repair cells. Here we have demonstrated that MSCs containing gold nanoparticles (GNPs) whose surface has been functionalized with PEG show accelerated cell migration, successful scaffold colonization and regeneration. We report the impact of GNPs on the migration (by the wound healing assay), and proliferation (by flow cytometry analysis and by the detection of metabolic mitochondrial activity) on the behaviour of different cell lines including MSCs, HeLa cells, and human dermal fibroblasts. We conclude that GNPs are easily internalized by MSCs causing an increase in their migration rate, mediated by actin and tubulin with a 4-fold increased expression level of those proteins. We also demonstrate that MSCs containing GNPs are able to successfully colonize fibrin and PCL-based scaffolds and that an enhanced osteoblastic differentiation is reached when using the nanoparticle-laden cells compared to untreated cells used as a control. These results highlight the potential use of MSCs as therapeutic nanoparticle-carriers in regenerative medicine.

Fabrication of nanostructured M13 bacteriophage films on titanium surfaces

2D aligned films prepared from engineered M13 bacteriophages (phage) have potential applications in tissue-regeneration and energy devices. TBP54–M13 phage specifically binds to acid-alkali treated titanium (Ti) surface. In this study, polyvinyl pyrrolidone–treated TBP54–M13 phage films were fabricated on Ti surfaces. The resultant film exhibited uniform nanostructure and favorable stability. This film has potential applications in surface multi–functionalization and patterning of Ti implants.

Concise Review: Balancing Stem Cell Self-Renewal and Differentiation with PLZF.

In recent years, the highly conserved promyelocytic leukemia zinc finger (PLZF, also known as ZBTB16, ZNF145) has attracted attention as a multifunctional transcription factor involved in major biological processes during development. As a transcription factor, PLZF shows tight regulation in its cell-type-specific and stage-specific expression patterns. Emerging evidence shows that PLZF regulates the balance of self-renewal and differentiation in stem cells. However, the gene regulatory network of PLZF is only beginning to be understood. In this review, we discuss the diverse functions of PLZF, in particular its role in self-renewal versus differentiation of stem cells. We also discuss the current state of knowledge on the gene regulatory network of PLZF, in conjunction with its upstream factors, post-translational modifications and binding cofactors for multiprotein complexes. This review aims to provide the reader with an in-depth understanding of the molecular mechanisms underlying PLZF and the potential applications in tissue regeneration.

Protein‐Affinitive Polydopamine Nanoparticles as an Efficient Surface Modification Strategy for Versatile Porous Scaffolds Enhancing Tissue Regeneration

Porous scaffolds for tissue regeneration are often functionalized with extracellular matrix proteins to enhance surface/cell interactions and tissue regeneration. However, continuous coatings produced by commonly used surface modification strategies may preclude cells from contacting and sensing the chemical and physical cues of the scaffold. Here, it is shown that polydopamine nanoparticles (PDA‐NPs) tightly adhere on various scaffolds to form nanostructures, and the coverage can be finely tuned. Furthermore, the PDA‐NPs have good affinity to a variety of proteins and peptides. Thus, the PDA‐NPs act as an anchor to immobilize signal biomolecules on scaffolds, and consequently promote cell activity and tissue regeneration. β‐Tricalcium phosphate (TCP) scaffolds decorated with PDA‐NPs demonstrate excellent osteoinductivity and bone‐regeneration performance due to the protein affinity of PDA‐NPs and the intrinsic bioactive characteristics of TCP scaffolds. In summary, PDA‐NPs with excellent affinity for protein adhesion represent a versatile platform to modify porous scaffolds while not compromising the biological functions of the scaffolds, and might have potential applications in tissue regeneration.