Good Bioactivity Research Articles

Effects of Nanometer Hydroxyapatite Aqueous Solution on Anaerobic Motor Ability of Mice

Nanometer hydroxyapatite is a new biomaterial with development potential. Its main components are very similar to those found in animal teeth. It has good biocompatibility and bioactivity. Can be closely bound to human tissue, repair tissue. With relatively more biosorption sites, it can be used as a protein carrier as an important strategy to fight cancer or promote the efficiency of tissue repair. It is widely used in biomedical fields, such as release carrier and tissue repair. With the development of modern medicine, the performance and application of nanometer hydroxyapatite are required. The purpose of this paper is to observe the effect of nanometer hydroxyapatite hydrosol on the anaerobic exercise ability of mice, and explore the mechanism of nanometer hydroxyapatite hydrosol on the anaerobic exercise ability of mice, which is of great significance for the application of nanometer hydroxyapatite in medicine and competitive sports. In this experiment, mathematical statistics were used to analyze the anaerobic swimming exhaustion time of mice in the nanometer hydroxyapatite injection group, sodium bicarbonate injection group, distilled water injection group and blank control group. The blood lactic acid content and immediate skeletal muscle lactic acid content of mice after anaerobic exercise were determined by statistical method. Finally, big data analysis method was used to fit the data and analyze the myocardial lactic acid value, skeletal muscle glycogen content and myocardial muscle glycogen content of mice injected with nano-hydroxyapatite sol after anaerobic swimming exhaustion. The experimental data showed that after the injection of nanometer hydroxyapatite hydrosol, the movement ability of mice increased. Experimental data showed that the nanometer hydroxyapatite hydrosol could improve the anaerobic exercise ability of mice, by neutralizing the lactic acid produced by the anaerobic exercise blood cells and cardiac muscle cells of mice, and prevent the accumulation of lactic acid, thereby increasing the anaerobic exercise ability by 40%, which is of great significance for athletes' exercise guidance in competitive sports.

Pharmacokinetics, Mechanism, and Docking Study of Antioxidant Aryl‐Bisthiourea Derivatives for Alzheimer's Disease

AbstractNovel aryl‐bisthiourea derivatives (3 a–3 j) were synthesized by a two‐step route for the study of free‐radical scavenging property and acetylcholinesterase enzyme (AChE) inhibition study. The effect of the electronic environment on the aryl structure of ArBTU on the AChE inhibition was studied. Lineweaver‐Burk plot was used for kinetic study of inhibition of AChE by using ArBTU derivatives which exhibited very good bioactivity of inhibition against acetylcholinesterase enzyme. Central Nervous System (CNS) permeability and the Blood‐Brain Barrier values of all ArBTU derivatives (3 a–3 j) were also similar to the reference value (>−2 logPS< −3 and >−0.3 log BB< −1), respectively. The molecular docking study of derivative 3 g presented a very good interactions with tested protein. The mechanism of AChE inhibition was found from the kinetic studies of novel ArBTU derivatives. A pharmacokinetic study of AChE inhibition was also evaluated. ArBTU derivatives (3 a–3 j) exhibited the best lead‐like potential. Molecular docking study described the binding ability of the highly effective derivative 3 g with the acetylcholinesterase enzyme.

Activity of a SDHI fungicide penflufen and the characterization of natural-resistance in Fusarium fujikuroi

The occurrence of bakanae disease of rice caused by the fungus Fusarium fujikuroi in Zhejiang Province has become increasingly aggravated in recent years, concomitant with the development of resistance to the widely applied fungicides, prochloraz and phenamacril. In this study, the activity of a novel succinate dehydrogenase inhibitor (SDHI) fungicide, penflufen, against different fungi was evaluated in addition to the potential of penflufen in controlling F. fujikuroi infections. Penflufen exhibited good bioactivity against F. fujikuroi, but weak activity against Fusarium spp. and other investigated plant-pathogenic fungi including Colletotrichum spp. In addition to inhibiting mycelial growth, penflufen effectively inhibited F. fujikuroi conidium production. For germination, penflufen could effectively inhibit that of small conidia, but only delay the germination of large conidia. In addition, the sensitivity to penflufen among 100 F. fujikuroi isolates that were collected in areas that were never exposed to SDHIs was determined based on mycelium growth. Sensitivities surprisingly exhibited bimodal distributions, indicating the presence of natural resistance. Cross-resistance was not observed between penflufen in F. fujikuroi and two fungicides that have been extensively applied in field including prochloraz (a DMI) and phenamacril (a 2-cyanoacrylate fungicide), nor with the three SDHIs, fluopyram, benzovindiflupyr, and pydiflumetofen. Additional analysis identified five different point mutations in SDH-A (i.e., at residues 46, 225, 283, 430, and 586) of naturally resistant isolates. These results inform the potential application of the new SDHI fungicide penflufen for managing crop diseases and understanding possible resistance mechanisms among pathogens.

Tantalum oxide submicro-particles into microporous coating on polyimide possessing antibacterial property and inducing cellular response for orthopedic application

Surface characteristics of the biomaterials have significant effects on response of osteoblast and formation of new bone tissue. In this study, to improve the bio-performance of polyimide (PI) as an implantable material for bone substitute, concentrated sulfuric acid suspension with tantalum (V) oxide (vTO) submicro-particles of 10w% (PIST10) and 15w% (PIST15) was utilized to modify PI surface. After sulfonation, microporous coatings including vTO particles were created on PI (PIST10 and PIST15) while microporous coating without vTO particles was also created on PI (PIS). Results showed that surface roughness, hydrophilicity and protein adsorption of PIST15 was remarkably higher than PIST10 and PIS. Furthermore, after soaking into simulated body fluid (SBF), no apatite mineralization on PIS was found, while PIST15 with high vTO content exhibited better apatite mineralization compared with PIST10. Moreover, PIS showed low antibacterial property, while PIST15 with high vTO content revealed better antibacterial property compared with PIST10. In addition, cellular response (such as adhesion, proliferation and alkaline phosphatase activity) of bone marrow stromal cells (BMSC) of rat to PIST15 was higher than PIST10 and PIS. In conclusion, the microporous coating of PIST15 including vTO submicro-particles possessed good antibacterial property and bioactivity, which significantly promoted the responses of BMSC. Therefore, PIST15 has potential application prospects for bone substitute.

Bone induction and defect repair by true bone ceramics incorporated with rhBMP-2 and Sr

Objective: To study the bone induction and defect repair of true bone ceramics (TBC) combined with rhBMP-2 and Sr. Methods: MC3T3-E1 cells were used to evaluate the bioactivity of the composite. Cell proliferation activity was detected by CCK-8, ALP activity was detected by p-nitrophenyl phosphate (PNPP), and the differences of material surface topography were observed by scanning electron microscopy (SEM). Bone induction was verified by the implantation in nude mice. The rabbit femoral condyle defect model was achieved to verify the bone defect repair ability of the material. Results: SEM results showed nearly the same surface morphology and cell proliferation quantified by CCK-8 showed that compared with TBC, both TBC&Sr and TBC&BMP-2&Sr had a significant promoting effect (P < 0.05). ALP activity result showed that the ALP activity of TBC&BMP-2&Sr was significantly higher than that of TBC alone (P < 0.05). The bone induction result showed that TBC&Sr had a small amount of new bone formation, and the new bone area was only 2.5 ± 0.11%. The bone induction activity of TBC&BMP-2&Sr was the highest, the new bone area was up to 75.36 ± 4.21%. Histological result of bone defect repair showed that TBC&BMP-2&Sr was also the highest, the new bone area was up to 72.42 ± 3.14%. The repair effect of TBC& BMP-2 was second, and better than that of TBC&Sr. Conclusion: TBC combined with rhBMP-2 and Sr had the good bioactivity, obvious bone conduction and bone defect repair performance, laying the foundation of clinical application potentially.

Immobilizing type I collagen via natural cross-linker genipin to enhance the osteogenic responses to titanium implant surface

Titanium (Ti) surface, with an essentially bioinert character, is not easy to actively initiate interactions with surrounding biological tissue. In this study, we developed a novel surface modification to enhance the osteogenic response to Ti surface in orthopedic and dental implant applications. The proposed surface modification combined alkaline treatment and type I collagen immobilization through using a natural cross-linker genipin. A variety of experiments were used to characterize the resulting surfaces in terms of morphology, chemistry, roughness, hydrophilicity, and bioactivity. We also assessed the responses of human bone marrow mesenchymal stem cells (hMSCs) to Ti surfaces in terms of adhesion, migration, proliferation, mineralization, and differentiation. Results showed that the modified Ti surfaces revealed a hydrophilic (water and diiodomethane contact angles <22°) nano-/submicron-scaled porous network porosity with surface roughness Ra ~0.1 μm and good bioactivity (Ca/P formation ability). The collagen-immobilized Ti surfaces with good coating adhesion was shown to facilitate the mineralization of the extracellular matrix and the expressions of specific osteogenic markers (osteopontin, bone sialoprotein, and osteocalcin) in hMSCs, thanks to improved cell adhesion and migration. Overall, the proposed Ti implant surface modification proved highly effective in terms of promoting osteogenic responses in vitro.

The Effect of Strontium-Substituted Hydroxyapatite Nanofibrous Matrix on Osteoblast Proliferation and Differentiation.

Natural bone tissue consists primarily of bioapatite and collagen. Synthetic hydroxyapatite (HA) possesses good biocompatibility, bioactivity, and osteoconductivity due to its chemical and biological similarity to bioapatite. Hence, HA has been widely used as a bone graft, cell carrier and drug/gene delivery carrier. Moreover, strontium-substituted hydroxyapatite (SrHA) can enhance osteogenic differentiation and inhibit adipogenic differentiation of mesenchymal stem cells. Hence, SrHA has the potential to be used as a bone graft for bone regeneration. It is widely accepted that cell adhesion and most cellular activities are sensitive to the topography and molecular composition of the matrix. Electrospun polymer or polymer-bioceramic composite nanofibers have been demonstrated to enhance osteoblast differentiation. However, to date, no studies have investigated the effect of nanofibrous bioceramic matrices on osteoblasts. In this study, hydroxyapatite nanofiber (HANF) and strontium-substituted hydroxyapatite nanofiber (SrHANF) matrices were fabricated by electrospinning. The effect of the HANF components on MG63 osteoblast-like cells was evaluated by cell morphology, proliferation, alkaline phosphatase activity (ALP) and gene expression levels of RUNX2, COLI, OCN and BSP. The results showed that MG63 osteoblast-like cells exhibited higher ALP and gene expression levels of RUNX2, COLI, BSP and OCN on the SrHANF matrix than the HANF matrix. Hence, SrHANFs could enhance the differentiation of MG63 osteoblast-like cells.

Construction of tissue-engineered skin with rete ridges using co-network hydrogels of gelatin methacrylated and poly(ethylene glycol) diacrylate

Tissue-engineered skin, as a promising skin substitute, can be used for in vitro skin research and skin repair. However, most of research on tissue-engineered skin tend to ignore the rete ridges (RRs) microstructure, which enhances the adhesion between dermis and epidermis and provides a growth environment for epidermal stem cells. Here, we prepared and characterized photocurable gelatin methacrylated (GelMA) and poly(ethylene glycol) diacrylate (PEGDA) co-network hydrogels with different concentrations. Using a UV curing 3D printer, resin molds were designed and fabricated to create three-dimensional micropatterns and replicated onto GelMA-PEGDA scaffolds. Human keratinocytes (HaCaTs) and human skin fibroblasts (HSFs) were co-cultured on the hydrogel scaffold to prepare tissue-engineered skin. The results showed that 10%GelMA-2%PEGDA hydrogel provides the sufficient mechanical properties and biocompatibility to prepare a human skin model with RRs microstructure, that is, it presents excellent structural support, suitable degradation rate, good bioactivity and is suitable for long-term culturing. Digital microscope image analyses showed the micropattern was well-transferred onto the scaffold surface. Both in vitro and in vivo experiments confirmed the formation of the epidermal layer with undulating microstructure. In wound healing experiments, hydrogel can significantly accelerate wound healing. This study provides a simple and powerful way to mimic the structures of human skin and can make a contribution to skin tissue engineering and wound healing.

Preparation and Properties of Multilayer Ca/P Bio-Ceramic Coating by Laser Cladding

In order to enhance the bioactivity and wear resistance of titanium (Ti) and its alloy for use as an implant surface, a multilayer Ca/P (calcium/phosphorus) bio-ceramic coating on a Ti6Al4V alloy surface was designed and prepared by a laser cladding technique, using the mixture of hydroxyapatite (HA) powder and Ti powder as a cladding precursor. The main cladding process parameters were 400 W laser power, 3 mm/s scanning speed, 2 mm spot diameter and 30% lapping rate. When the Ca/P ceramic coating was immersed in simulated body fluid (SBF), ion exchange occurred between the coating and the immersion solution, and hydroxyapatite (HA) was induced and deposited on its surface, which indicated that the Ca/P bio-ceramic coating had good bioactivity. The volume wear of Ca/P ceramic coating was reduced by 43.2% compared with that of Ti6Al4V alloy by the pin-disc wear test, which indicated that the Ca/P bio-ceramic coating had better wear resistance.

Investigation on Biocompatibility and Mechanical Properties of Ti15Mg Alloy

In this research work, bioactive Ti15Mg alloy was prepared by powder metallurgy route to investigate its biocompatibility and mechanical properties. Many tests were performed including X-ray diffraction; optical microscope analysis, scanning electron microscope analysis, ultrasonic wave test, corrosion behavior test, Static immersion test, and the wet sliding wear test. The XRD result shows that the prepared alloy sample consist of (α-Ti phase) and Mg. The microstructure of the prepared alloy sample consisted of a biodegradable Mg or pore and alpha titanium. The effect of the Mg content on degradability was tested based on simulated body fluid of Ringer solutions using electrochemical corrosion. The findings indicate that an elastic modulus of 47GPa exhibits the alloy. There were low corrosion rates of the alloy. The Ti matrix remained integrity after 14 days of immersion in the Ringer solutions, and the magnesium phase dissolved in the solution, causing a layer to form on the alloy. The wear behavior of the prepared ally at wet sliding conditions was evaluated using pin on disc method. The in vitro analysis showed good biocompatibility with Ti15Mg alloy. The prepared alloy demonstrates good biocompatibility and bioactivity.

Vanillin-bioglass cross-linked 3D porous chitosan scaffolds with strong osteopromotive and antibacterial abilities for bone tissue engineering

Chitosan scaffolds crosslinked by current methods insufficiently meet the demands of bone tissue engineering applications. We developed a novel effective crosslinking technique by using the natural and safe vanillin together with bioglass microparticles to generate an antibacterial, osteoconductive, and mechanically robust 3D porous chitosan-vanillin-bioglass (CVB) scaffold. In addition to the significantly improved mechanical properties, the CVB scaffolds had high porosity (>90%) and interconnected macroporous structures. Our data suggested that the crosslinking mainly resulted from the Schiff base reactions between the aldehydes of vanillin and amines of chitosan, together with the hydrogen and ionic bonds formed within them. Importantly, the CVB scaffolds not only showed good biocompatibility, bioactivity, and strong antibacterial ability but also significantly promoted osteoblastic differentiation, mineralization in vitro, and ectopic bone formation in vivo. Thus, the CVB scaffolds hold great promise for bone tissue engineering applications based on their robust mechanical properties, osteoconductivity, and antibacterial abilities.

Structural characterization, in vitro bioactivity, and antibacterial evaluation of low silver-doped bioactive glasses

Four bioactive glasses (70 SiO2-(20-X) CaO-10 P2O5) containing low concentrations of silver (X Ag2O; where X = 0.5, 1, and 1.5 mol%) were synthesized by the conventional sol-gel method. Physical and structural characterization was realized using Fourier Transform Infrared (FT-IR), Thermogravimetric Analysis (TGA), X-ray Diffraction analysis (XRD), and Scanning Electron Microscopy (SEM-EDX). Acellular bioactivity tests were performed by immersion in the SBF solution. Escherichia coli and Staphylococcus aureus were used to evaluate the antibacterial activity of the prepared Ag-doped bioglasses. While FTIR, DRX, and SEM analysis displayed good acellular bioactivity for all bioactive glasses (Ag–70S), the antibacterial activity confirms well the bactericidal effect of 70S 1Ag and 70S 1.5Ag through total growth inhibition (100%) of the two pathogenic bacteria. It is also important to mention that low silver-doped bioglass nanoparticles (Ag2O ≤ 1.5 mol%) could be a required multifunctional candidate in bone tissue engineering.

Experimental Dental Composites Containing a Novel Methacrylate-Functionalized Calcium Phosphate Component: Evaluation of Bioactivity and Physical Properties.

The aim of this study was to synthesize and characterize a novel methacrylate-functionalized calcium phosphate (MCP) to be used as a bioactive compound for innovative dental composites. The characterization was accomplished by attenuated total reflectance Fourier-transform infrared spectroscopy (ATR-FTIR), scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS). The incorporation of MCP as a bioactive filler in esthetic dental composite formulations and the ability of MCP containing dental composites to promote the precipitation of hydroxyapatite (HAp) on the surfaces of those dental composites was explored. The translucency parameter, depth of cure, degree of conversion, ion release profile, and other physical properties of the composites were studied with respect to the amount of MCP added to the composites. Composite with 3 wt.% MCP showed the highest flexural strength and translucency compared to the control composite and composites with 6 wt.% and 20 wt.% MCP. The progress of the surface precipitation of hydroxyapatite on the MCP containing dental composites was studied by systematically increasing the MCP content in the composite and the time of specimen storage in Dulbecco’s phosphate-buffered solution with calcium and magnesium. The results suggested that good bioactivity properties are exhibited by MCP containing composites. A direct correlation between the percentage of MCP in a composite formulation, the amount of time the specimen was stored in PBS, and the deposition of hydroxyapatite on the composite’s surface was observed.

Therapeutic Effects of the Addition of Fibroblast Growth Factor-2 to Biodegradable Gelatin/Magnesium-Doped Calcium Silicate Hybrid 3D-Printed Scaffold with Enhanced Osteogenic Capabilities for Critical Bone Defect Restoration.

Worldwide, the number of bone fractures due to traumatic and accidental injuries is increasing exponentially. In fact, repairing critical large bone defects remains challenging due to a high risk of delayed union or even nonunion. Among the many bioceramics available for clinical use, calcium silicate-based (CS) bioceramics have gained popularity due to their good bioactivity and ability to stimulate cell behavior. In order to improve the shortcomings of 3D-printed ceramic scaffolds, which do not easily carry growth factors and do not provide good tissue regeneration effects, the aim of this study was to use a gelatin-coated 3D-printed magnesium-doped calcium silicate (MgCS) scaffold with genipin cross-linking for regulating degradation, improving mechanical properties, and enhancing osteogenesis behavior. In addition, we consider the effects of fibroblast growth factor-2 (FGF-2) loaded into an MgCS scaffold with and without gelatin coating. Furthermore, we cultured the human Wharton jelly-derived mesenchymal stem cells (WJMSC) on the scaffolds and observed the biocompatibility, alkaline phosphatase activity, and osteogenic-related markers. Finally, the in vivo performance was assessed using micro-CT and histological data that revealed that the hybrid bioscaffolds were able to further achieve more effective bone tissue regeneration than has been the case in the past. The above results demonstrated that this type of processing had great potential for future clinical applications and studies and can be used as a potential alternative for future bone tissue engineering research, as well as having good potential for clinical applications.

Fabrication and characterization of bioactive zirconia-based nanocrystalline glass-ceramics for dental abutment

Zirconia-based ceramics are becoming a popular biomaterial in dental implantology due to their natural silver-white color, excellent mechanical properties, and good biocompatibility. However, zirconia-based ceramics are biologically inert, which limits their ability to integrate with the surrounding human tissues. To solve this problem, the bioactive elements of calcium (Ca) and phosphorus (P) were doped in high-strength ZrO2–SiO2 nanocrystalline glass-ceramics (NCGCs) to overcome the biological inertness of ZrO2-based ceramics. XRD results showed that tetragonal zirconia (t-ZrO2) and monoclinic zirconia (m-ZrO2) were the only two crystalline phases after spark plasma sintering. Ca and P dopants acted as destabilizer of t-ZrO2, enhancing its transformability to m-ZrO2 during sintering. The amount of t-ZrO2 exerted significant effects on the average flexural strength of the NCGCs. The NCGC with 45 mol% ZrO2 were composed of 64.5 vol% t-ZrO2 and 35.5 vol% m-ZrO2 after sintering at 1230 °C. And, the average flexural strength and Vickers hardness of the NCGC was 615 MPa and 1049 HV, respectively. In comparison, the NCGC with 65 mol% ZrO2 were composed of 12.6 vol% t-ZrO2 and 87.4 vol% m-ZrO2 after sintering at 1150 °C. The average flexural strength and Vickers hardness of the NCGC was 293 MPa and 839 HV, respectively. Interestingly, the NCGCs exhibited a plastic deformation behavior during flexural strength test, which was different from traditional brittle ceramics. The ion release results demonstrated that Ca2+ and Si4+ ions kept on releasing from the surface of the material. The formation of hydroxyapatite in the in-vitro apatite formation test indicated that the NCGCs had good biological activity. The doped ZrO2-based NCGCs combined moderate strength and good bioactivity. Hence, the NCGCs show promising potential to be used in sub-gingival regions, such as dental abutments.

Identification of Severe Acute Respiratory Syndrome Coronavirus-2 inhibitors through in silico structure-based virtual screening and molecular interaction studies.

The novel coronavirus Severe Acute Respiratory Syndrome Coronavirus‐2 (SARS‐CoV‐2) or COVID‐19 has caused a worldwide pandemic. The fatal virus has affected the health of human beings as well as the socio‐economic situation all over the world. To date, no concrete medicinal solution has been proposed to combat the viral infection, calling for an urgent, strategic, and cost‐effective drug development approach that may be achievable by applying targeted computational and virtual screening protocols. Immunity is the body's natural defense against disease‐causing pathogens, which can be boosted by consuming plant‐based or natural food products. Active constituents derived from natural sources also scavenge the free radicals and have anti‐inflammatory activities. Herbs and spices have been used for various medicinal purposes. In this study, 2,96 365 natural and synthetic derivatives (ligands) belonging to 102 classes of compounds were obtained from PubChem and assessed on Lipinski's parameters for their potential bioavailability. Out of all the derivatives, 3254 obeyed Lipinski's rule and were virtually screened. The 115 top derivatives were docked against SARS‐CoV‐2, SARS‐CoV, MERS‐CoV, and HCoV‐HKV1 main proteases (Mpros) as receptors using AutoDock Vina, AutoDock, and iGEMDOCK 2.1. The lowest binding energy was exhibited by ligands 2 and 6 against all the four Mpros. The molecular dynamic simulation was also performed with ligand 6 using the GROMACS package. Good bioactivity scores, absorption, distribution, metabolism, excretion, and toxicity profile and drug‐like pharmacokinetic parameters were also obtained. Hydroxychloroquine was used as the control drug.

Multi-metal ions doped hydroxyapatite coatings via electrochemical methods for antibacterial and osteogenesis

The Hydroxyapatite (HA) coating on the surface of titanium (Ti) with good bioactivity for osseointegration ability, however, the lack of antibacterial properties. In this study, the pulse electrochemical method was used to oxidize and polymerize pyrrole (Py) into polypyrrole (PPy) in situ, and PPy was used as the regulator of HA nanoparticles (HA-NPs) and metal particles to construct uniform PPy@HA/ZnO-Cu, PPy@HA/ZnO-Ag, PPy@HA/Ag-Cu, and PPy@HA/ZnO-Ag-Cu nanocomposite coatings on the Ti substrate. The antibacterial rates of four groups of composite coatings against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) were all 100%. The PPy@HA/ZnO-Ag composite coating could promote the growth and proliferation of Vascular Endothelial Cells (VECs) and Bone Marrow Mesenchymal Stem Cells (BMSCs). Therefore, the PPy@HA/ZnO-Ag composite coating has the best osteoinductive ability among all the groups, excellent antibacterial property, angiogenic and osteogenic capability, which can be used as an ideal implant coating.

PBAT hollow porous microfibers prepared via electrospinning and their functionalization for potential peptide release

Although microfiber (MF) loaded polypeptides have been widely studied in the field of medicine, load control and slow release remain significant challenges. Herein, polybutylene adipate terephthalate (PBAT) hollow porous MFs (HPMFs) were prepared by improving and regulating the groups and structures of the MFs to address these challenges. The capacity of the HPMFs for the loading of polypeptide can be improved. Measurements involving the use of X-ray photoelectron, energy-dispersive, and ultraviolet (UV) spectroscopies in conjunction with scanning electron microscopy measurements showed that the amount of polypeptide (arginylglycylaspartic acid, RGD) loaded on the HPMFs was significantly higher than that loaded on the MFs. Animal cell experiments revealed that PBAT grafted MAH has good bioactivity. By loading RGD onto HPMFs and MFs, RGD@HPMFs and RGD@MFs were obtained. A study on HeLa and A549 cancer cells showed that the inhibition rates of RGD@HPMFs were higher than that of RGD@MFs by 14.1% and 6.9%, respectively. The results obtained herein show that HPMF scaffold preparation by improving the material groups and regulating the structure of MFs can address the challenges associated with control of the load and sustained release of polypeptides and other drugs.

Microstructural, mechanical properties and strengthening mechanism of DLP produced β-tricalcium phosphate scaffolds by incorporation of MgO/ZnO/58S bioglass

The inherent brittleness of bioceramics restricts their applications in load-bearing implant, although they possess good biocompatibility and bioactivity. ZnO, MgO and 58S bioglass (BG) were incorporated as additives to further improve the mechanical properties and biocompatibility of β-TCP and ZnO/MgO/BG-β-TCP composite scaffolds were manufactured via digital light processing (DLP). The composite with the best comprehensive performance was selected for degradation behavior and biocompatibility evaluation. The effects of different proportions of ZnO/MgO/BG on mechanical strength were analyzed and ZnO0·5/MgO1/BG2-β-TCP (ZMBT) samples exhibited superior mechanical strength. The improvement by 272% and 99% respectively was achieved in fracture toughness and compressive strength with the optimal recipe. The enhancement effect is realized through phase transition, alterative sliding actions and transgranular fracture to effectively prevent the load transfer combining the functions of bioglass and metal oxide. ZMBT scaffolds exhibited a more desirable pH environment and an enhanced ability of apatite-mineralization formation, meanwhile Si4+, Mg2+ and Zn2+ were gradually released from scaffolds. Furthermore, in vitro evaluation indicated that ZMBT scaffolds presented not only excellent cell attachment, proliferation, alkaline phosphatase (ALP) activity, but they up-regulated osteogenic gene (ALP, OCN, Runx2). These results suggest that the addition of ZnO/MgO/BG to DLP-printed β-TCP scaffolds offer a smart strategy to fabricate porous scaffolds with conspicuously better biological and physicochemical properties including compressive strength, bioactivity, osteogenesis and osteogenesis-related gene expression. Metal-oxide and BG synergistically enhanced the mechanical and biological properties which make the ZMBT scaffolds a strong candidate for bone repair applications.

Virtual high-throughput screening (VHTS), three-dimensional quantitative structure- activity and relationship (3D-QSAR) and molecular docking studies of novel phyto-inhibtors of topoisomerase II alpha

Topoisomerase II alpha catalyses and guides the unknotting of DNA by creating double transient breaks in the DNA using a conserved tyrosine as the catalytic residue. Topoisomerase II alpha has been shown to be overexpressed in numerous types of cancers and it is a target for multiple chemotherapeutic agents. Many DNA topoisomerase inhibitors have been identified from natural sources and have been reviewed in many reports as anticancer agents. In the present study, a total of 240 phytochemicals characterized from four reported anticancer plants (Anacardium occidentale, Andrographis paniculata, Cannabis sativa and Tinospora cordifolia) were obtained from literatures and screened against the binding pocket of topoisomerase II alpha. From the pool of phytochemicals only 7-o-methylcyanidin, 20-betaecdysone, Andropanoside and Palmatoside-G qualified as Phyto-compounds with good oral bioactivity when subjected to the Lipinski’s rule of five. Bioassay data containing the IC50 of compounds screened against topoisomerase II alpha was used to generate a regression model using the 3D-QSAR techniques. A very viable model with R2 = 0.954, adjusted R2 = 0.908, Pearson R = 0.977, cross validation Q2 = 0.851, Standard Error of Estimate = 0.125, F = (20.803, p &lt; 0.05) and Durbin-Watson constant = 1.613 was obtained. The 3D-QSAR result shows that Andropanoside and 20-betaecdysone may be better inhibitors of topoisomerase II alpha catalytic site than the standard drug, Etoposide. To further confirm this, the molecular interactions of Andropanoside and 20-betaecdysone were compared to those of Etoposide using the ligand interaction interface of Maestro environment.