Collagen type I promotes osteogenic differentiation of amniotic membrane-derived mesenchymal stromal cells in basal and induction media

Osteogenic Differentiation Potential of iMSCs on GelMA-BG-MWCNT Nanocomposite Hydrogels

The ability of bone biomaterials to promote osteogenic differentiation is crucial for the repair and regeneration of osseous tissue. The development of a temporary bone substitute is of major importance in enhancing the growth and differentiation of human-derived stem cells into an osteogenic lineage. In this study, nanocomposite hydrogels composed of gelatin methacryloyl (GelMA), bioactive glass (BG), and multiwall carbon nanotubes (MWCNT) were developed to create a bone biomaterial that mimics the structural and electrically conductive nature of bone that can promote the differentiation of human-derived stem cells. GelMA-BG-MWCNT nanocomposite hydrogels supported mesenchymal stem cells derived from human induced pluripotent stem cells, hereinafter named iMSCs. Cell adhesion was improved upon coating nanocomposite hydrogels with fibronectin and was further enhanced when seeding pre-differentiated iMSCs. Osteogenic differentiation and mature mineralization were promoted in GelMA-BG-MWCNT nanocomposite hydrogels and were most evidently observed in the 70-30-2 hydrogels, which could be due to the stiff topography characteristic from the addition of MWCNT. Overall, the results of this study showed that GelMA-BG-MWCNT nanocomposite hydrogels coated with fibronectin possessed a favorable environment in which pre-differentiated iMSCs could better attach, proliferate, and further mature into an osteogenic lineage, which was crucial for the repair and regeneration of bone.

Human dental pulp stem cells derived extracellular matrix promotes mineralization via Hippo and Wnt pathways

Extracellular matrix (ECM) is an intricate structure providing the microenvironment niche that influences stem cell differentiation. This study aimed to investigate the efficacy of decellularized ECM derived from human dental pulp stem cells (dECM_DPSCs) and gingival-derived mesenchymal stem cells (dECM_GSCs) as an inductive scaffold for osteogenic differentiation of GSCs. The proteomic analysis demonstrated that common and signature matrisome proteins from dECM_DPSCs and dECM_GSCs were related to osteogenesis/osteogenic differentiation. RNA sequencing data from GSCs reseeded on dECM_DPSCs revealed that dECM_DPSCs upregulated genes related to the Hippo and Wnt signaling pathways in GSCs. In the inhibitor experiments, results revealed that dECM_DPSCs superiorly promoted GSCs osteogenic differentiation, mainly mediated through Hippo and Wnt signaling. The present study emphasizes the promising translational application of dECM_DPSCs as a bio-scaffold rich in favorable regenerative microenvironment for tissue engineering.

Use of biosilica to improve loading and delivery of bone morphogenic protein 2

The clinical utility of bone morphogenetic protein 2 (BMP2) is limited because of the poor attraction between BMP2 and carriers, resulting in low loading efficiency and initial burst release. Here, the high binding affinity of BMP2 to the biosilica surface was utilized to overcome this limitation. Atomic force microscopy revealed that BMP2 bound nearly 8- and 2-fold more strongly to biosilica-coated hydroxyapatite than to uncoated and plain silica-coated hydroxyapatite, respectively. To achieve controlled release, collagen was introduced between the silica layers on hydroxyapatite, which was optimized by adjusting the collagen concentration and number of layers. The optimal biosilica/collagen formulation induced sustained BMP2 release without compromising loading efficiency. BMP2 combined with the mentioned formulation led to an increase in osteogenesis, as compared to the combination of BMP2 with either biosilica-coated or non-coated hydroxyapatite in vitro. In rat calvarial defect models, the biosilica/collagen-coated hydroxyapatite with 1 μg BMP2 showed 26 % more bone regeneration than the same dose of BMP2-loaded hydroxyapatite and 10.6 % more than hydroxyapatite with 2.5-fold dose of BMP2. Using BMP2 affinity carriers coated with biosilica/collagen allows for more efficacious in situ loading and delivery of BMP2, making them suitable for the clinical application of growth factors through a soaking method.

Biomechanical and Biological Characterization of XGel, a Human-Derived Hydrogel for Stem Cell Expansion and Tissue Engineering

Hydrogels are 3D scaffolds used as alternatives to in vivo models for disease modeling and delivery of cells and drugs. Existing hydrogel classifications include synthetic, recombinant, chemically defined, plant- or animal-based, and tissue-derived matrices. There is a need for materials that can support both human tissue modeling and clinically relevant applications requiring stiffness tunability. Human-derived hydrogels are not only clinically relevant, but they also minimize the use of animal models for pre-clinical studies. This study aims to characterize XGel, a new human-derived hydrogel as an alternative to current murine-derived and synthetic recombinant hydrogels that features unique physiochemical, biochemical, and biological properties that support adipocyte and bone differentiation. Rheology studies determine the viscosity, stiffness, and gelation features of XGel. Quantitative studies for quality control support consistency in the protein content between lots. Proteomics studies reveal that XGel is predominantly composed of extracellular matrix proteins, including fibrillin, collagens I-VI, and fibronectin. Electron microscopy of the hydrogel provides phenotypic characteristics in terms of porosity and fiber size. The hydrogel demonstrates biocompatibility as a coating material and as a 3D scaffold for the growth of multiple cell types. The results provide insight into the biological compatibility of this human-derived hydrogel for tissue engineering.

Sonomechanobiology: Vibrational stimulation of cells and its therapeutic implications

All cells possess an innate ability to respond to a range of mechanical stimuli through their complex internal machinery. This comprises various mechanosensory elements that detect these mechanical cues and diverse cytoskeletal structures that transmit the force to different parts of the cell, where they are transcribed into complex transcriptomic and signaling events that determine their response and fate. In contrast to static (or steady) mechanostimuli primarily involving constant-force loading such as compression, tension, and shear (or forces applied at very low oscillatory frequencies (≤ 1 Hz) that essentially render their effects quasi-static), dynamic mechanostimuli comprising more complex vibrational forms (e.g., time-dependent, i.e., periodic, forcing) at higher frequencies are less well understood in comparison. We review the mechanotransductive processes associated with such acoustic forcing, typically at ultrasonic frequencies (> 20 kHz), and discuss the various applications that arise from the cellular responses that are generated, particularly for regenerative therapeutics, such as exosome biogenesis, stem cell differentiation, and endothelial barrier modulation. Finally, we offer perspectives on the possible existence of a universal mechanism that is common across all forms of acoustically driven mechanostimuli that underscores the central role of the cell membrane as the key effector, and calcium as the dominant second messenger, in the mechanotransduction process.

Human Mesenchymal Stromal Cells Derived from Perinatal Tissues: Sources, Characteristics and Isolation Methods

Mesenchymal stromal/stem cells (MSCs) derived from perinatal tissues have become indispensable sources for clinical applications due to their superior properties, ease of accessibility and minimal ethical concerns. MSCs isolated from different placenta (PL) and umbilical cord (UC) compartments exhibit great potential for stem cell-based therapies. However, their biological activities could vary due to tissue origins and differences in differentiation potentials. This review provides an overview of MSCs derived from various compartments of perinatal tissues, their characteristics and current isolation methods. Factors affecting the yield and purity of MSCs are also discussed as they are important to ensure consistent and unlimited supply for regenerative medicine and tissue engineering.

Cell-binding peptides on the material surface guide stem cell fate of adhesion, proliferation and differentiation

Human cells, especially stem cells, need to communicate and interact with extracellular matrix (ECM) proteins, which not only serve as structural components but also guide and support cell fate and properties such as cell adhesion, proliferation, survival and differentiation. The binding of the cells with ECM proteins or ECM-derived peptides via cell adhesion receptors such as integrins activates several signaling pathways that determine the cell fate, morphological change, proliferation and differentiation. The development of synthetic ECM protein-derived peptides that mimic the biological and biochemical functions of natural ECM proteins will benefit academic and clinical application. Peptides derived from or inspired by specific ECM proteins can act as agonists of each ECM protein receptor. Given that most ECM proteins function in cell adhesion via integrin receptors, many peptides have been developed that bind to specific integrin receptors. In this review, we discuss the peptide sequence, immobilization design, reaction method, and functions of several ECM protein-derived peptides. Various peptide sequences derived from mainly ECM proteins, which are used for coating or grafting on dishes, scaffolds, hydrogels, implants or nanofibers, have been developed to improve the adhesion, proliferation or differentiation of stem cells and to culture differentiated cells. This review article will help to inform the optimal choice of ECM protein-derived peptides for the development of scaffolds, implants, hydrogels, nanofibers and 2D cell culture dishes to regulate the proliferation and direct the differentiation of stem cells into specific lineages.

UPLC-ESI-Q-TOF-MSE-based metabolomics analysis of Acer mono sap and evaluation of osteogenic activity in mouse osteoblast cells

Investigation of phytochemicals and bioactive molecules is tremendously vital for the applications of new plant resources in chemistry, food, and medicine. In this study, the chemical profiling of sap of Acer mono (SAM), a Korean syrup known for its anti-osteoporosis effect, was performed using UPLC-ESI-Q-TOF-MS^E analysis. A total of 23 compounds were identified based on the mass and fragmentation characteristics and most of the compounds have significant biomedical applications. The in vitro antioxidant assessment of SAM indicated excellent activity by scavenging DPPH and ABTS-free radicals and were found to be 23.35 mg mL^-1 and 29.33 mg mL^-1, respectively, as IC₅₀ concentrations. As well, the in vitro proliferation effect of the SAM was assessed against mouse MC3T3-E1 cells, and the results showed that the SAM enhanced the proliferation of the cells, and 12.5 mg mL^-1 and 25 mg mL^-1 of SAM were selected for osteogenic differentiation. The morphological analysis clearly evidenced the SAM enhanced the osteogenic activity in MC3T3-E1 cells by the increased deposition of extracellular calcium and nodule formation. Moreover, the qRT-PCR analysis confirmed the increased expression of osteoblast marker gene expression including ALP, osteocalcin, osteopontin, collagen1α1, Runx2, and osterix in SAM-treated MC3T3-E1 cells. Together, these results suggest that SAM possesses osteogenic effects and can be used for bone regeneration and bone loss-associated diseases such as osteoporosis.

pH-Dependent Release of Vancomycin from Modularly Assembled Collagen Laminates

To prevent surgical site infections, antibiotics can be released from carriers made of biomaterials, such as collagen, that support the healing process and are slowly degraded in the body. In our labs we have developed collagen laminates that can be easily assembled and bonded on-site, according to medical needs. As shown previously, the asymmetric assembly leads to different release rates at the major faces of the laminate. Since the pH changes during the wound healing and infection, we further examined the effect of an acidic and alkaline pH, in comparison to pH 7.4 on the release of vancomycin from different collagen samples. For this purpose, we used an additively manufactured sample holder and quantified the release by HPLC. Our results show that the pH value does not have any influence on the total amount of released vancomycin (atelocollagen sponge pH 5.5: 71 ± 2%, pH 7.4: 68 ± 8%, pH 8.5: 74 ± 3%, bilayer laminate pH 5.5: 61 ± 6%, pH 7.4: 69 ± 4% and pH 8.5: 67 ± 3%) but on the time for half-maximal release. At an acidic pH of 5.5, the swelling of the atelocollagen sponge is largely increased, leading to a 2-3 h retarded release, compared to the physiological pH. No changes in swelling were observed at the basic pH and the compound release was 1-2 h delayed. These effects need to be considered when choosing the materials for the laminate assembly.

A new hydrogel with fluorapatite nanoparticles for osteogenic differentiation of human adipose-derived stem cells in tissue engineering field

Since scaffolds are engineered to support functional tissue formation, their design and materials play an essential role in medical fields by providing different mechanical function. The aim of this study was to investigate the synthesis and structural characterization of collagen-gelatin (COL-GEL) composite scaffolds containing fluorapatite (FA) nanoparticles as well as evaluation of the osteogenic differentiation of human adipose-derived stem cells (hADSCs). First, the composite scaffolds were evaluated using Fourier transform infrared spectroscopy, scanning electron microscopy, and X-ray diffraction. The cytotoxicity of scaffolds and various concentrations of FA nanoparticles was studied through MTT assay and acridine orange/ethidium bromide staining. Next, the differentiated hADSCs were analyzed using Alizarin red and von Kossa staining, calcium content assay, alkaline phosphatase (ALP) activity, real-time RT-PCR, and immunocytochemical analyses. According to the characterization analyses, the composite scaffolds were properly integrated. The results also illustrated that COL-GEL composite scaffolds in the presence of FA nanoparticles not only showed no cytotoxicity but also increased ALP activity and calcium deposition as well as the expression of osteogenic genes, including Runx2, Col-I, ALP, and osteocalcin and the synthesis of proteins such as osteocalcin and osteopontin in vitro. The obtained data were confirmed by Alizarin red and von Kossa staining. These results are very promising for further tissue engineering experiments, in which FA nanoparticle incorporation into COL-GEL composite scaffolds is a novel approach that improves the surface COL-GEL composite scaffolds for tissue engineering application in vitro.

Gene Expression Profiles of Human Mesenchymal Stromal Cells Derived from Wharton’s Jelly and Amniotic Membrane before and after Osteo-Induction Using NanoString Platform

The use of perinatal mesenchymal stem cells (MSCs) in bone tissue regeneration and engineering to substitute bone marrow MSCs has drawn great interest due to their high yield, ease of procurement, multilineage differentiation potential and lack of ethical concerns. Although amniotic membrane (AM) and Wharton’s jelly (WJ)-derived MSCs have been widely shown to possess osteogenic differentiation potential, the intrinsic properties determining their osteogenic capacity remain unclear. Here, we compared gene expression profiles of AM- and WJ-MSCs at basal and osteogenic conditions by using the NanoString Stem Cell Panel containing regulatory genes associated with stemness, self-renewal, Wnt, Notch and Hedgehog signalling pathways. At basal condition, WJ-MSCs displayed higher expression in most genes regardless of their functional roles in self-renewal, adhesion, or differentiation signalling pathways. After osteo-induction, elevated expression of self-renewal genes ADAR and PAFAH1B1 was observed in AM-MSCs, while stemness genes MME and ALDH1A1 were upregulated in WJ-MSC. Both MSCs showed differences in genes associated with ligands, receptors and ubiquitin ligases of the Notch pathway. In addition, further evidence was demonstrated in some signalling molecules including CTBPs, protein kinases, phosphatases, RHOA, RAC1. Downstream targets HES1 and JUN especially showed higher expression in non-induced WJ-MSCs. Hedgehog genes initially expressed in both MSCs were downregulated in WJ-MSCs during osteogenesis. This study has provided insights into the intrinsic biological differences that may lead to their discrimination in therapeutic intervention.

Mechanotransduction through adhesion molecules: Emerging roles in regulating the stem cell niche

Stem cells have been shown to play an important role in regenerative medicine due to their proliferative and differentiation potential. The challenge, however, lies in regulating and controlling their potential for this purpose. Stem cells are regulated by growth factors as well as an array of biochemical and mechanical signals. While the role of biochemical signals and growth factors in regulating stem cell homeostasis is well explored, the role of mechanical signals has only just started to be investigated. Stem cells interact with their niche or to other stem cells via adhesion molecules that eventually transduce mechanical cues to maintain their homeostatic function. Here, we present a comprehensive review on our current understanding of the influence of the forces perceived by cell adhesion molecules on the regulation of stem cells. Additionally, we provide insights on how this deeper understanding of mechanobiology of stem cells has translated toward therapeutics.

Collagen Modulates the Biological Characteristics of WJ-MSCs in Basal and Osteoinduced Conditions

Transcriptomic analysis revealed mesenchymal stem/stromal cells (MSCs) from various origins exhibited distinct gene and protein expression profiles dictating their biological properties. Although collagen type 1 (COL) has been widely studied in bone marrow MSCs, its role in regulating cell fate of Wharton jelly- (WJ-) MSCs is not well understood. In this study, we investigated the effects of collagen on the characteristics of WJ-MSCs associated with proliferation, surface markers, adhesion, migration, self-renewal, and differentiation capabilities through gene expression studies. The isolated WJ-MSCs expressed positive surface markers but not negative markers. Gene expression profiles showed that COL not only maintained the pluripotency, self-renewal, and immunophenotype of WJ-MSCs but also primed cells toward lineage differentiations by upregulating BMP2 and TGFB1 genes. Upon osteoinduction, WJ-MSC-COL underwent osteogenesis by switching on the transcription of BMP6/7 and TGFB3 followed by activation of downstream target genes such as INS, IGF1, RUNX2, and VEGFR2 through p38 signalling. This molecular event was also accompanied by hypomethylation at the OCT4 promoter and increase of H3K9 acetylation. In conclusion, COL provides a conducive cellular environment in priming WJ-MSCs that undergo a lineage specification upon receiving an appropriate signal from extrinsic factor. These findings would contribute to better control of fate determination of MSCs for therapeutic applications related to bone disease.

Effect of Puerarin on Osteogenic Differentiation in vitro and on New Bone Formation in vivo

Purpose

Puerarin (C₂₁H₂₀O₁₀) is a phytoestrogen that possesses various pharmacological effect, and several researches have revealed the relationship between puerarin and bone metabolism. This study was aimed to evaluate the potential influence of puerarin on the proliferation and osteogenic differentiation of rat bone marrow-derived mesenchymal stem cells (BMSCs) as well as on new bone formation following rapid maxillary expansion (RME) model in rats.

Methods

Rat BMSCs were adopted, and the cell proliferation was detected by cell-counting kit-8 (CCK-8) assay in vitro experiments. Alkaline phosphatase (ALP) activity and alizarin red staining were analyzed quantitatively to show extracellular matrix mineralization. The mRNA and protein expression levels were used to detect osteogenic differentiation of BMSCs. In vivo bone regeneration was analyzed in a rat RME model. Eighteen 6-week-old male Wistar rats were divided into 3 groups: group 1 without any treatment, group 2 received RME and saline solution (15mg/kg), group 3 received RME and puerarin solution (15mg/kg). After 2 weeks, micro-computed tomography (Micro-CT), hematoxylin and eosin (HE) staining, and Masson staining were used to detect the new bone formation and morphological changes. Besides, ALP and bone morphogenetic protein 2 (BMP2) expression levels in mid-palatal suture were evaluated by immunohistochemical staining.

Results

The results showed that puerarin upregulates cell proliferation dose-dependently. ALP activity and mineralized matrix generation were clearly enhanced at certain specific concentrations (10⁻⁵ and 10⁻⁶ mol/L); the expression levels of the osteoblast-related genes and proteins were increased. The measurement of micro-CT imaging revealed that puerarin significantly promoted new bone formation. Concomitantly, the histological examinations showed that puerarin solution enhanced osteogenesis in mid-palatal suture.

Conclusion

Those works indicated that puerarin regulates osteogenesis in vitro and exerts a beneficial impact on bone regeneration in vivo, revealing that puerarin treatment may become one of the potential keys for improving the stability and preventing relapse of RME.

The role of the Smad2/3/4 signaling pathway in osteogenic differentiation regulation by ClC-3 chloride channels in MC3T3-E1 cells

Background

ClC-3 chloride channels promote osteogenic differentiation. Transforming growth factor-β1 (TGF-β1) and its receptors are closely related to ClC-3 chloride channels, and canonical TGF-β1 signaling is largely mediated by Smad proteins. The current study aimed to explore the role of the Smad2/3/4 signaling pathway in the mechanism by which ClC-3 chloride channels regulate osteogenic differentiation in osteoblasts.

Methods

First, real-time PCR and western blotting were used to detect the expression of Smad and mitogen-activated protein kinase (MAPK) proteins in response to ClC-3 chloride channels. Second, immunocytochemistry, coimmunoprecipitation (Co-IP) and immunofluorescence analyses were conducted to assess formation of the Smad2/3/4 complex and its translocation to the nucleus. Finally, markers of osteogenic differentiation were determined by real-time PCR, western blotting, ALP assays and Alizarin Red S staining.

Results

ClC-3 chloride channels knockdown led to increased expression of Smad2/3 but no significant change in p38 or Erk1/2. Furthermore, ClC-3 chloride channels knockdown resulted in increases in the formation of the Smad2/3/4 complex and its translocation to the nucleus. In contrast, the inhibition of TGF-β1 receptors decreased the expression of Smad2, Smad3, p38, and Erk1/2 and the formation of the Smad2/3/4 complex. Finally, the expression of osteogenesis-related markers were decreased upon ClC-3 and Smad2/3/4 knockdown, but the degree to which these parameters were altered was decreased upon the knockdown of ClC-3 and Smad2/3/4 together compared to independent knockdown of ClC-3 or Smad2/3/4.

Conclusions

The Smad2/3 proteins respond to changes in ClC-3 chloride channels. The Smad2/3/4 signaling pathway inhibits osteogenic differentiation regulation by ClC-3 chloride channels in MC3T3-E1 cells.

Recombinant expression a novel fibronectin-collage fusion peptide modulating stem cell stemness via integrin β3

Abstract

Constructing bionic extracellular matrix (ECM) is an attractive proposition for tissue engineering and clinical regeneration therapy involving the stemness of stem cells. Here, a novel recombinant protein fibronectin-collagen peptide (FCP) was designed to modulate the function of ECM expressed by Picha. pastoris strain X33. This FCP promotes cell migration and adhesion and maintains rBMSC stemness by binding integrin β3. Its effects were blocked by both integrin β3 siRNA and the integrin β3 inhibitor Cilengitide. A template-independent ab initio prediction modeling approach is the best approach to construct a stable FCP protein model, which predicts the binding sites between FCP and integrin β3. FCP may be used in the in vitro culture and clinical regeneration of stem cells that highly express integrin β3, such as hematopoietic stem cells. The study provides information on the molecular structure of FCP and its bioactivity, which can be used to design new compounds.

Key points

• Design a novel recombinant fibronectin-collagen peptide biomimetic ECM.

• FCP promotes cell adhesion, migration, and proliferation.

• Predicted and verified FCP structure and affinity with integrin β3.

• FCP binds integrin β3 to maintain rBMSC stemness.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00253-022-11965-4.

Biologically modified implantation as therapeutic bioabsorbable materials for bone defect repair

For decades, researches have concentrated on the mechanical properties, biodegradation, and biocompatibility of implants used in the therapy of large size bone defect. In vivo studies demonstrate that bioabsorbable bone substitute materials can reduce the risk of common symptoms such as inflammation and osteonecrosis caused by bio-inert materials after long-term implantation. Several organic, inorganic, and composite materials have been approved for clinical application, based on their unique characteristics and advantages. Although some artificial bioabsorbable bone substitute materials have been used for years, there are still some disadvantages existing, such as low mechanical strength, high brittleness, and low degradation rate. Therefore, novel bioabsorbable composite materials biomaterials have been developed for bone defect repair. In this review, we provide an overview of the development of artificial bioabsorbable bone substitute materials and highlight the advantages and disadvantages. Furthermore, recent advances in bioabsorbable bone substitute materials used in bone defect repair are outlined. Finally, we discuss current challenges and further developments in the clinical application of bioabsorbable bone substitute materials.