Enhanced osteoinduction of electrospun scaffolds with assemblies of hematite nanoparticles as a bioactive interface

Biomaterials combined with ADSCs for bone tissue engineering: current advances and applications

In recent decades, bone tissue engineering, which is supported by scaffold, seed cells and bioactive molecules (BMs), has provided new hope and direction for treating bone defects. In terms of seed cells, compared to bone marrow mesenchymal stem cells, which were widely utilized in previous years, adipose-derived stem cells (ADSCs) are becoming increasingly favored by researchers due to their abundant sources, easy availability and multi-differentiation potentials. However, there is no systematic theoretical basis for selecting appropriate biomaterials loaded with ADSCs. In this review, the regulatory effects of various biomaterials on the behavior of ADSCs are summarized from four perspectives, including biocompatibility, inflammation regulation, angiogenesis and osteogenesis, to illustrate the potential of combining various materials with ADSCs for the treatment of bone defects. In addition, we conclude the influence of additional application of various BMs on the bone repair effect of ADSCs, in order to provide more evidences and support for the selection or preparation of suitable biomaterials and BMs to work with ADSCs. More importantly, the associated clinical case reports and experiments are generalized to provide additional ideas for the clinical transformation and application of bone tissue engineering loaded with ADSCs.

Lactoferrin Mediates Enhanced Osteogenesis of Adipose-Derived Stem Cells: Innovative Molecular and Cellular Therapy for Bone Repair

A prospective source of stem cells for bone tissue engineering is adipose-derived stem cells (ADSCs), and BMP-2 has been proven to be highly effective in promoting the osteogenic differentiation of stem cells. Rarely has research been conducted on the impact of lactoferrin (LF) on ADSCs' osteogenic differentiation. As such, in this study, we examined the effects of LF and BMP-2 to assess the ability of LF to stimulate ADSCs' osteogenic differentiation. The osteogenic medium was supplemented with the LF at the following concentrations to culture ADSCs: 0, 10, 20, 50, 100, and 500 μg/mL. The Cell Counting Kit-8 (CCK-8) assay was used to measure the proliferation of ADSCs. Calcium deposition, alkaline phosphatase (ALP) staining, real-time polymerase chain reaction (RT-PCR), and an ALP activity assay were used to establish osteogenic differentiation. RNA sequencing analysis was carried out to investigate the mechanism of LF boosting the osteogenic development of ADSCs. In the concentration range of 0-100 μg/mL, LF concentration-dependently increased the proliferative vitality and osteogenic differentiation of ADSCs. At a dose of 500 μg/mL, LF sped up and enhanced differentiation, but inhibited ADSCs from proliferating. LF (100 and 500 μg/mL) produced more substantial osteoinductive effects than BMP-2. The PI3 kinase/AKT (PI3K/AKT) and IGF-R1 signaling pathways were significantly activated in LF-treated ADSCs. The in vitro study results showed that LF could effectively promote osteogenic differentiation of ADSCs by activating the PI3K/AKT and IGF-R1 pathways. In our in vitro investigation, an LF concentration of 100 μg/mL was optimal for osteoinduction and proliferation. Our study suggests that LF is an attractive alternative to BMP-2 in bone tissue engineering. As a bioactive molecule capable of inducing adipose stem cells to form osteoblasts, LF is expected to be clinically used in combination with biomaterials as an innovative molecular and cellular therapy to promote bone repair.

Biodegradable and biocompatible synthetic polymers for applications in bone and muscle tissue engineering

In medicine, tissue engineering has made significant advances. Using tissue engineering techniques, transplant treatments result in less donor site morbidity and need fewer surgeries overall. It is now possible to create cell-supporting scaffolds that degrade as new tissue grows on them, replacing them until complete body function is restored. Synthetic polymers have been a significant area of study for biodegradable scaffolds due to their ability to provide customizable biodegradable and mechanical features as well as a low immunogenic effect due to biocompatibility. The food and drug administration has given the biodegradable polymers widespread approval after they showed their reliability. In the context of tissue engineering, this paper aims to deliver an overview of the area of biodegradable and biocompatible synthetic polymers. Frequently used synthetic biodegradable polymers utilized in tissue scaffolding, scaffold specifications, polymer synthesis, degradation factors, as well as fabrication methods are discussed. In order to emphasize the many desired properties and corresponding needs for skeletal muscle and bone, particular examples of synthetic polymer scaffolds are investigated. Increased biocompatibility, functionality and clinical applications will be made possible by further studies into novel polymer and scaffold fabrication approaches.  

Broad-Spectrum Theranostics and Biomedical Application of Functionalized Nanomaterials

Nanotechnology is an important branch of science in therapies known as “nanomedicine” and is the junction of various fields such as material science, chemistry, biology, physics, and optics. Nanomaterials are in the range between 1 and 100 nm in size and provide a large surface area to volume ratio; thus, they can be used for various diseases, including cardiovascular diseases, cancer, bacterial infections, and diabetes. Nanoparticles play a crucial role in therapy as they can enhance the accumulation and release of pharmacological agents, improve targeted delivery and ultimately decrease the intensity of drug side effects. In this review, we discussthe types of nanomaterials that have various biomedical applications. Biomolecules that are often conjugated with nanoparticles are proteins, peptides, DNA, and lipids, which can enhance biocompatibility, stability, and solubility. In this review, we focus on bioconjugation and nanoparticles and also discuss different types of nanoparticles including micelles, liposomes, carbon nanotubes, nanospheres, dendrimers, quantum dots, and metallic nanoparticles and their crucial role in various diseases and clinical applications. Additionally, we review the use of nanomaterials for bio-imaging, drug delivery, biosensing tissue engineering, medical devices, and immunoassays. Understandingthe characteristics and properties of nanoparticles and their interactions with the biological system can help us to develop novel strategies for the treatment, prevention, and diagnosis of many diseases including cancer, pulmonary diseases, etc. In this present review, the importance of various kinds of nanoparticles and their biomedical applications are discussed in much detail.

3D magnetic nanocomposite scaffolds enhanced the osteogenic capacities of rat bone mesenchymal stem cells in vitro and in a rat calvarial bone defect model by promoting cell adhesion

Magnetic scaffolds incorporated with iron oxide nanoparticles (IONPs) are biocompatible and present excellent osteogenic properties. However, the underlying mechanism is unclear. In this study, 3D-printed poly(lactic-co-glycolic acid) scaffolds were coated with IONPs using layer-by-layer assembly (Fe-scaffold) to prepare magnetic scaffolds. The effects of this modification on osteogenesis were investigated by comparison with untreated scaffolds (Uncoated-scaffold). The results showed that the proliferation of rat bone mesenchymal stem cells (rBMSCs) on the Fe-scaffold was enhanced compared with those on the Uncoated-scaffold (p < 0.05). The alkaline phosphatase activity and expression levels of osteogenic-related genes of cells on the Fe-scaffold were higher than those on the Uncoated-scaffold (p < 0.05). Fe-scaffold was found to promote the cell adhesion compared with Uncoated-scaffold, including increasing the adhered cell number, promoting cell spreading and upregulating the expression levels of adhesion-related genes integrin α1 and β1 and their downstream signaling molecules FAK and ERK1/2 (p < 0.05). Moreover, the amount of new bone formed in rat calvarial defects at 8 weeks decreased in the order: Fe-scaffold > Uncoated-scaffold > Blank-control (samples whose defects were left empty) (p < 0.05). Therefore, 3D magnetic nanocomposite scaffolds enhanced the osteogenic capacities of rBMSCs in vitro and in a rat calvarial bone defect model by promoting cell adhesion. The mechanisms were attributed to the alteration in its hydrophilicity, surface roughness, and chemical composition.

Hydroxyapatite/NELL-1 Nanoparticles Electrospun Fibers for Osteoinduction in Bone Tissue Engineering Application

Background

As commonly bone defect is a disease of jaw that can seriously affect implant restoration, the bioactive scaffold can be used as potential systems to provide effective repair for bone defect.

Purpose

A osteoinductive bone tissue engineering scaffold has been prepared in order to explore the effect of bioactive materials on bone tissue engineering.

Methods

In this study, NELL-1 nanoparticles (Chi/NNP) and nano hydroxyapatite were incorporated in composite scaffolds by electrospinning and characterized using TEM, SEM, contact angle, tensile tests and in vitro drug release. In vitro biological activities such as MC3T3-E1 cell attachment, proliferation and osteogenic activity were studied.

Results

With the addition of nHA and nanoparticles, the fiber diameter of PCL/BNPs group, PCL/NNPs group and PCL/nHA/NNPs group was significantly increased. Moreover, the hydrophilic hydroxyl group and amino group presented in nHA and nanoparticles had improved the hydrophilicity of the composite fibers. The composite electrospun containing Chi/NNPs can form a double protective barrier which can effectively prolong the release time of NELL-1 growth factor. In addition, the hydroxyapatite/NELL-1 nanoparticles electrospun fibers can promote attachment, proliferation, differentiation of MC3T3-E1 cells and good cytocompatibility, indicating better ability of inducing osteogenic differentiation.

Conclusion

A multi-functional PCL/nHA/NNPs composite fiber with long-term bioactivity and osteoinductivity was successfully prepared by electrospinning. This potential composite could be used as scaffolds in bone tissue engineering application after in vivo studies.

Development of Inula graveolens (L.) Plant Extract Electrospun/Polycaprolactone Nanofibers: A Novel Material for Biomedical Application

Recently, there has been a growing interest in research on nanofibrous scaffolds developed by electrospinning bioactive plant extracts. In this study, the extract material obtained from the medicinal plant Inula graveolens (L.) was loaded on polycaprolactone (PCL) electrospun polymeric nanofibers. The combined mixture was prepared by 5% of I. graveolens at 8% (PCL) concentration and electrospun under optimal conditions. The chemical analysis, morphology, and crystallization of polymeric nanofibers were carried out by (FT-IR) spectrometer, scanning electron microscopy (SEM), and XRD diffraction. Hydrophilicity was determined by a contact angle experiment. The strength was characterized, and the toxicity of scaffolds on the cell line of fibroblasts was finally investigated. The efficiency of nanofibers to enhance the proliferation of fibroblasts was evaluated in vitro using the optimal I. graveolens/PCL solutions. The results show that I. graveolens/PCL polymeric scaffolds exhibited dispersion in homogeneous nanofibers around 72 ± 963 nm in the ratio 70/30 (V:V), with no toxicity for cells, meaning that they can be used for biomedical applications.

Optimization of Topography and Surface Properties of Polyacrylonitrile-Based Electrospun Scaffolds via Nonoclay Concentrations and its Effect on Osteogenic Differentiation of Human Mesenchymal Stem Cells

Nowadays, mesenchymal stem cells (MSCs) are the most widely used cell sources for bone regenerative medicine. Electrospun polyacrylonitrile (PAN)-based scaffolds play an important role in bone tissue engineering due to their good mechanical properties, which could be enhanced by the presence of nanoparticles such as nanoclay. This study evaluated the in-vitro effect of different concentrations of nanoclay in surface characteristic properties of PAN-based electrospun nanofiber scaffolds and the osteogenic differentiation ability of adipose-derived mesenchymal stem cells (AD-MSCs). After electrospinning nanofibers, their structure were assessed through some characterization tests. Then AD-MSCs isolation and characterization were done, and the cell attachment and the biocompatibility were determined. Finally, osteogenic differentiation-related markers, genes, and proteins were studied. Clay-PAN25% electrospun nanofiber scaffold could support attachment, proliferation, and osteogenic differentiation of AD-MSCs better than other groups. Also, nanoclay could enhance the properties of PAN-based scaffolds, such as fiber diameter, topography, surface charge, hydrophilicity, roughness, and degradation, as well as osteogenic differentiation of cells. As a result, Clay-PAN25% with the highest concentration of nanoclay was found as a promising biodegradable and cost-effective scaffold for osteogenic differentiation of AD-MSCs.

Use of nanoparticles in skeletal tissue regeneration and engineering

Bone and osteochondral defects represent one of the major causes of disabilities in the world. Derived from traumas and degenerative pathologies, these lesions cause severe pain, joint deformity, and loss of joint motion. The standard treatments in clinical practice present several limitations. By producing functional substitutes for damaged tissues, tissue engineering has emerged as an alternative in the treatment of defects in the skeletal system. Despite promising preliminary clinical outcomes, several limitations remain. Nanotechnologies could offer new solutions to overcome those limitations, generating materials more closely mimicking the structures present in naturally occurring systems. Nanostructures comparable in size to those appearing in natural bone and cartilage have thus become relevant in skeletal tissue engineering. In particular, nanoparticles allow for a unique combination of approaches (e.g. cell labelling, scaffold modification or drug and gene delivery) inside single integrated systems for optimized tissue regeneration. In the present review, the main types of nanoparticles and the current strategies for their application to skeletal tissue engineering are described. The collection of studies herein considered confirms that advanced nanomaterials will be determinant in the design of regenerative therapeutic protocols for skeletal lesions in the future.