Hydrogels are crosslinked polymer chains with three-dimensional (3D) network structures, which can absorb relatively large amounts of fluid. Because of the high water content, soft structure, and ...porosity of hydrogels, they closely resemble living tissues. Research in recent years shows that hydrogels have been applied in various fields, such as agriculture, biomaterials, the food industry, drug delivery, tissue engineering, and regenerative medicine. Along with the underlying technology improvements of hydrogel development, hydrogels can be expected to be applied in more fields. Although not all hydrogels have good biodegradability and biocompatibility, such as synthetic hydrogels (polyvinyl alcohol, polyacrylamide, polyethylene glycol hydrogels, etc.), their biodegradability and biocompatibility can be adjusted by modification of their functional group or incorporation of natural polymers. Hence, scientists are still interested in the biomedical applications of hydrogels due to their creative adjustability for different uses. In this review, we first introduce the basic information of hydrogels, such as structure, classification, and synthesis. Then, we further describe the recent applications of hydrogels in 3D cell cultures, drug delivery, wound dressing, and tissue engineering.
The bone defects healing are always associated with post implantation infections; hence biomaterials rules significant role for orchestration of defective bone. In this study, we synthesized ...biocomposite scaffold by combining polycaprolactone (PCL), wollastonite (Ws) and metal ions (Cu) by electrospinning technique. The manufactured scaffolds (PCL/Ws andPCL/Cu–Ws) were subjected to physio‐chemical characterization by scanning electron microscopy, energy dispersive X‐ray spectroscopy, Fourier Transform Infra Red Spectroscopy (FTIR) and XRD. The surface topography of the scaffolds was found to be micro‐fibrous in nature and each fiber was cylindrical in structure. The exogenous biomineralization and protein adsorption capacity of these scaffolds were studied. Enhanced amount of protein was adsorbed on PCL/Cu‐Ws than PCL/Ws scaffold after incubating for 48 hr in foetal bovine serum (FBS) also the biomineralization shown to be promoted the apatite formation in vitro. The synthesized PCL/Cu–Ws scaffold was biocompatible to mouse mesenchymal stem cells and enhanced the mRNA expressionof osteoblastic specific marker genes including alkaline phosphatase and type I collagen and major transcription factor Runx2 in the presence of osteogenic medium indicates the osteoconductive nature of the scaffolds. The amount of calcium deposition and promotion of osteoblast differentiation and mineralization on human osteoblast cells was confirmed by alizarin red staining. The fabricated scaffolds possess potent antibacterial effect against Staphylococcu aureus and Escherichia coli. Hence, our outcomes confirmed that the PCL/Ws and PCL/Cu–Ws scaffolds promote bonesynthesis by cell proliferation and differentiation suitable for applications in bone regeneration orbone defects.
Bone is a flexible and electro active tissue that is vulnerable to various traumatic injuries. The self-healing of damaged bone tissue towards reconstruction is limited due to the lack of proper ...niche compliances. Nevertheless, the classical grafting techniques like autograft/allograft for bone repair pose challenges like bacterial infections and donor-site morbidity with unsatisfactory outcomes. The use of appropriate biomaterial with osteogenic potential can meet these challenges. In this regard, bioactive glass ceramics is widely used as a bone filler or graft material because of its bonding affinity to bone leading towards bone reconstruction applications without the challenge of post implant infections. Hence, the current study is aimed at addressing this potentiality of zinc (Zn) for doped the bioglass at nano-scale advantages for bone tissue repair. Since, Zn has been demonstrated to have not only antibacterial property but also the stimulatory effect on osteoblasts differentiation, mineralization by enhancing the osteogenic genes expression. In view of these, the present study is focused on sol–gel synthesis and pysico-chemical characterization of Zinc-doped bioglass nanoparticles (Zn-nBGC) and also analyzing its biological implications. The surface morphological and physiochemical characterizations using SEM, EDX, FT-IR and XRD analysis has shown the increased surface area of Zn-nBGC particles providing a great platform for biomolecular interaction, cytocompatibility, cell proliferation and osteogenic differentiation. The obtaining hydroxy apatite groups have initiated in vitro mineralization towards osteogenic lineage formation. Zn has not only involved in enhancing cellular actions but also strengthen the ceramic nanoparticles towards antibacterial application. Hence the finding suggests a biomaterial synthesis of better biomaterial for bone tissue engineering application by preventing post-operative bacterial infection.
Silk fibroin (SF) and hyaluronic acid (HA) were crosslinked by horseradish peroxidase (HRP)/H2O2, and 1,4-Butanediol di-glycidyl ether (BDDE), respectively, to produce HA/SF-IPN (interpenetration ...network) (HS-IPN) hydrogels. HS-IPN hydrogels consisted of a SF strain with a high content of tyrosine (e.g., strain A) increased viscoelastic modules compared with those with low contents (e.g., strain B and C). Increasing the quantities of SF in HS-IPN hydrogels (e.g., HS7-IPN hydrogels with weight ratio of HA/SF, 5:7) increased viscoelastic modules of the hydrogels. In addition, the mean pores size of scaffolds of the model hydrogels were around 38.96 ± 5.05 μm which was between those of scaffolds H and S hydrogels. Since the viscoelastic modulus of the HS7-IPN hydrogel were similar to those of human nucleus pulposus (NP), it was chosen as the model hydrogel for examining the differentiation of human bone marrow-derived mesenchymal stem cell (hBMSC) to NP. The differentiation of hBMSC induced by transforming growth factor β3 (TGF-β3) in the model hydrogels to NP cells for 7 d significantly enhanced the expressions of glycosaminoglycan (GAG) and collagen type II, and gene expressions of aggrecan and collagen type II while decreased collagen type I compared with those in cultural wells. In summary, the model hydrogels consisted of SF of strain A, and high concentrations of SF showed the highest viscoelastic modulus than those of others produced in this study, and the model hydrogels promoted the differentiation of hBMSC to NP cells.
Ischemia/reperfusion (I/R) injury causes the generation of many ROS such as H
O
and leads to vascular thrombosis, which causes tissue damage.
In this investigation, poly (lactideco-glycolide) ...(PLGA)-based nanoparticles are used for their anticoagulant and antioxidant properties in vascular therapy.
Both heparin and glutathione are entrapped on PLGA-stearylamine nanoparticles by layer-by-layer interactions.
The drug release rate is successfully controlled with only 10.3% of the heparin released after 96 hours. An H
O
-responsive platform is also developed by combining silk fibroin and horse peroxidase to detect H
O
in this drug delivery system. Besides, hyaluronic acid was decorated on the surface of nanoparticles to target the human bone marrow mesenchymal stem cells (hBMSCs) for cell therapy. The results of an in vitro study indicate that the nanoparticles could be taken up by hBMSCs within 2 hours and exocytosis occurred 6 hours after cellular uptake.
We propose that the multifunctional nanoparticles that are formed herein can be effectively delivered to the site of an I/R injury via the hBMSC homing effect. The proposed approach can potentially be used to treat vascular diseases, providing a platform for hBMSCs for the controlled delivery of a wide range of drugs.
Magnetic nanoparticles (MNPs) can be localized against hemodynamic forces in blood vessels with the application of an external magnetic field. In addition, PEGylation of nanoparticles may increase ...the half-life of nanocomposites in circulation. In this work, we examined the effect of PEGylation on the magnetic capture of MNPs in vivo.
Laser speckle contrast imaging and capillaroscopy were used to assess the magnetic capture of dextran-coated MNPs and red blood cell (RBC) flow in cremaster microvessels of anesthetized rats. Magnetic capture of MNPs in serum flow was visualized with an in vitro circulating system. The effect of PEGylation on MNP-endothelial cell interaction was studied in cultured cells using an iron assay.
In microcirculation through cremaster muscle, magnet-induced retention of 250 nm MNPs was associated with a variable reduction in RBC flow, suggesting a dynamic coupling of hemodynamic and magnetic forces. After magnet removal, faster restoration of flow was observed in PEG(+) than PEG(-) group, which may be attributed to a reduced interaction with vascular endothelium. However, PEGylation appears to be required for magnetic capture of 50 nm MNPs in microvessels, which was associated with increased hydrodynamic diameter to 130±6 nm in serum, but independent of the ς-potential.
These results suggest that PEGylation may enhance magnetic capture of smaller MNPs and dispersion of larger MNPs after magnet removal, which may potentially affect the targeting, pharmacokinetics and therapeutic efficacy.
This study investigated whether a nanometer scale of surface roughness could improve the adhesion and growth of human endothelial cells on a biomaterial surface. Different molecular weights or chain ...lengths of polyethylene glycol (PEG) were mixed and then grafted to a polyurethane (PU) surface, a model smooth surface, to form a nanometer (nm) scale of roughness for PU-PEG surfaces (PU-PEG
mix) while PEG with a molecular weight of 2000 was also grafted to PU to form PU-PEG
2000 for comparison. In addition, the concept was tested on cell-adhesive peptide Gly–Arg–Gly–Asp (GRGD) that was photochemically grafted to PU-PEG
mix and PU-PEG
2000 surfaces (e.g., PU-PEG
mix-GRGD and PU-PEG
2000-GRGD surfaces, respectively). To prepare GRGD-grafted PU-PEG
mix and PU-PEG
2000 surface, 0.025
m of GRGD-SANPAH (
N-Succinimidyl-6-4′-azido-2′-nitrophenylamino-hexanoate) solutions was grafted to PU-PEG
mix and PU-PEG
2000 by surface adsorption of the peptide and subsequent ultraviolet (UV) irradiation for photoreaction. The grafting efficiencies for GRGD to PU-PEG
mix and PU-PEG
2000 surfaces were about 67% for both surfaces, semi-quantitatively analyzed by an HPLC. The surface roughness, presented with a roughness parameter,
R
a, and the topography of the tested surfaces were both measured and imaged by an atomic force microscope (AFM). Among the
R
a values of the films, PU was the smoothest (e.g.,
R
a=1.53±0.20
nm,
n=3) while PU-PEG
mix was the roughest (e.g.,
R
a=39.79±10.48
nm,
n=4). Moreover,
R
a values for PU-PEG
mix and PU-PEG
mix-GRGD surfaces were about 20
nm larger than those for PU-PEG
2000 and PU-PEG
2000-GRGD, respectively, which were consistent with the topographies of the films. Human umbilical vein endothelial cells (HUVECs) were adhered and grown on the tested surfaces after 36
h of incubation. Among the films, HUVEC's adhesion on the surface of PU-PEG
mix-GRGD was the densest while that on the surface of PU-PEG
2000 was the sparsest. Also, the adhesion and growth of HUVECs for the roughness surfaces were statistically significantly better than that of smooth surface for both GRGD grafted and un-grafted surfaces, respectively. The viability for the growth of HUVECs on the tested surfaces analyzed by MTT assay also confirmed the efficacy of the increased surface roughness.
In conclusion, increased surface roughness of biomaterial surfaces even at 10–10
2
nm scale could enhance the adhesion and growth of HUVECs on roughness surfaces that could be useful for applications of tissue engineering.
The effects of the stiffness of substrates on the cell behaviours of human bone marrow‐derived mesenchymal stem cells (hBMSC) have been investigated, but the effects of the secondary structures of ...proteins in the substrates on the morphological transformation and differentiation of hBMSC have yet been elucidated. To investigate these issues, silk fibroin‐poly(ε‐caprolactone) SP cardiac patches of poly(ε‐caprolactone; P), on which is grafted by silk fibroin (SF) with various β‐sheet contents (or crystallinity) to provide various degrees of stiffness, were produced to examine the in vitro behaviours of hBMSC during proliferation, and cardiomyogenesis on the SP patches. β‐sheet contents of SF from 20% to 44% (SP20 to SP44, respectively) were induced on patches, which were examined by attenuated total reflection Fourier‐transform infrared (ATR‐FTIR) spectroscopy, and analysed using the Fourier self‐deconvolution method. The stiffness of the SP patches, quantified by their Young's moduli and elasticities, increased with the crystallinity of the SF. During 3 days of proliferation, hBMSC migrated and morphologically transformed into 3D microtissues with diameters of approximately 150–200 μm on low‐stiffness SP20 and SP30 patches, whereas 2D monolayers were observed on the SP37 and SP44 patches. The 3D microtissues/patch yielded more extensive in vitro cardiomyogenesis of hBMSC than the 2D cell monolayer with significantly higher expressions of all examined cardiac‐specific proteins after induction by 5‐aza. Notably, in vivo subcutaneously growing 3D microtissues on SP20 patches and a 2D monolayer on SP44 patches were preliminarily demonstrated in a rat model. Morphological transformations of hBMSC from a 2D monolayer to a 3D microtissue by low‐stiffness SP cardiac patches, promoting cardiomyogenesis, provide a new opportunity for cardiac tissue engineering.
Abstract Bone marrow mesenchymal stem cells/silk fibroin/hyaluronic acid (BMSC/SH) patches were implanted into myocardial infarction (MI) rat hearts to investigate the efficacies of them on enhancing ...left ventricular (LV) remodeling and cardiac repair. 45 rats were divided into four groups: Sham, MI (MI hearts, induced by a cryo-injury technique), SH and BMSC/SH (MI hearts with implantations of SH and BMSC/SH patches, respectively). After eight weeks of post-implantation, the patches for the SH and BMSC/SH groups were intact and well adhered on the MI zones with no and minor immunological responses, respectively, examined by a CD68 marker, while severe inflammation on the zones was observed for the MI group. The SH group showed the efficacy of cardiac repair on MI zones. Moreover, BMSC/SH group significantly improved the wall thickness of LV, assessed by echocardiography, and had high viability of delivery BMSC, largely reduced apoptosis, significantly promoted neo-vascularization and stimulated the secretions of various paracrine factors such as VEGF, examined by real-time PCR, in MI zones compared with those of the SH and MI groups. In conclusion, the therapeutic efficacies of using BMSC/SH patches for repairing MI hearts were demonstrated by showing the advantages of both bioactive SH patches and BMSC-based therapy.
This study spots light on combined Wound healing process conjoining blood coagulation, inflammation reduction, proliferation and remodeling of the cells. The objective is to overcome the drawbacks of ...conventional clinically applied wound dressings such as poor rigidity, porosity, mechanical potency and bactericidal activity. As nosocomial infection is a very common condition at the wound site, bio-adhesive materials with intrinsic antibacterial properties are used in clinical applications. Considering the provenability of Wollastonite Calcium silicate (CaSiO3) to regenerate the soft tissues by inducing vascularization and regeneration of fibroblast cells And the antibacterial potentiality of zinc in clinical applications, the present study focuses on synthesis of Zn-Ws particles and evaluation of its antimicrobial and wound healing potentialities towards skin tissue engineering applications. The compositional characterization by EDAS and FT-IR spectral analysis have substantiated the presence of major elements and corresponding band stretching associated with the synthesized particles whereas the particles morphology by SEM images have shown the size of the Ws and Zn-Ws to be 370 nm and 530 nm respectively. From the in vitro studies, skin regenerative potential of Zn-Ws was determined on promoting fibroblast cell (NIH3T3) proliferation by providing better adhesiveness, biocompatibility and cytocompatibility. The antibacterial property of Zn-Ws evaluation by minimum inhibitory concentration (MIC) and zone of inhibition (ZOI) methods against clinical isolates of Gram +Ve and Gram –Ve bacterial strains have confirmed that the addition of Zn has diminished the bacterial growth and also helped in degrading the bacterial biofilms. Thus it is summed up that the process of wound healing is expected to occur with reduced risk of post-injury infections by the presence of zinc-doping on wollastonite for skin tissue application.
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