Satisfactory Bioactivity Research Articles

Biological evaluation of ZrO2 composites modified with different ceramics additives

In this work, zirconia (ZrO2) composites modified with bioactive hydroxyapatite (HAp), hexagonal boron nitride (hBN), bioglass (BG), and bioglass with copper (BGCu) via the hydrothermal method were synthesized. The aim was to obtain highly bioactive and cytocompatible materials that could combine beneficial properties of inert and bioactive ceramics. Such materials could be applied as fillers for tooth extraction cavities, guaranteeing osseintegration without the need to introduce additional bone cements or other adhesives. It was proven that while all materials were favourable towards cells adhesion and growth, the HAp and BG-doped ones facilitated early adhesion, especially when compared to unmodified ZrO2. Only the HAp-doped materials showed satisfactory bioactivity results, with a well-developed apatite layer forming on their surfaces. This study confirms that the Hap-doped ZrO2 is suitable for treating bone defects.

Computational Evaluation of Bioactive Compounds from Dysphania ambrosioides Leaves.

Dysphania ambrosioides has been reported to have many medicinal properties, due to its possession of a multitude of biologically active molecules contained in its leaves. However, very few studies have been reported to evaluate their pharmacological properties. Consequently, in the present study, many computational tools have been performed to predict drug similarity and ADMET properties. Besides, the inhibitory potential of D.ambrosioides major compounds against Bacterial, Fungal and cardiovascular main receptor targets has been investigated. This study suggests that Carvone oxide, 5-Isopropenyl-2-Methylenecyclohexanol, and Caryophyllene oxide were the most active molecules belonging to D. ambrosioides Leaves, possessing drug-likeness with satisfactory bioactivity scores, having good pharmacokinetic values. Metabolism and toxicities were further studied using FAME3, GLORY, and pred-hERG. Slight cardiotoxicity and cytotoxicity were predicted, respectively, for Caryophyllene oxide and Carvone oxide, 5-Isopropenyl-2-Methylenecyclohexanol. Good inhibitory activities of the three compounds against Bacterial, Fungal, and Cardiovascular receptor targets. Hence, this is a comprehensive in silico approach to evaluate D.ambrosioides Leaves main phytocompounds in the background of its potential in future drug development.

Manufacture of titanium alloy materials with bioactive sandblasted surfaces and evaluation of osseointegration properties.

Titanium alloys are some of the most important orthopedic implant materials currently available. However, their lack of bioactivity and osteoinductivity limits their osseointegration properties, resulting in suboptimal osseointegration between titanium alloy materials and bone interfaces. In this study, we used a novel sandblasting surface modification process to manufacture titanium alloy materials with bioactive sandblasted surfaces and systematically characterized their surface morphology and physicochemical properties. We also analyzed and evaluated the osseointegration between titanium alloy materials with bioactive sandblasted surfaces and bone interfaces by in vitro experiments with co-culture of osteoblasts and in vivo experiments with a rabbit model. In our in vitro experiments, the proliferation, differentiation, and mineralization of the osteoblasts on the surfaces of the materials with bioactive sandblasted surfaces were better than those in the control group. In addition, our in vivo experiments showed that the titanium alloy materials with bioactive sandblasted surfaces were able to promote the growth of trabecular bone on their surfaces compared to controls. These results indicate that the novel titanium alloy material with bioactive sandblasted surface has satisfactory bioactivity and osteoinductivity and exhibit good osseointegration properties, resulting in improved osseointegration between the material and bone interface. This work lays a foundation for subsequent clinical application research into titanium alloy materials with bioactive sandblasted surfaces.

A dextrorotatory residues-incorporated bioactive dodecapeptide against enterohemorrhagic Escherichia coli

Aim: This study aims to report an engineered peptide zp39 with favorable bioactivity against enterohemorrhagic Escherichia coli (E. coli, EHEC). Its antibacterial mechanisms and application in a real food system are assessed. Methods: Spatial conformation of synthetic peptide zp39 (GIIAGIIiKIKk-NH2, lowercase letters indicate dextrorotatory amino acids) was predicted by PEPstrMOD and its secondary structure was further determined by circular dichroism (CD) spectroscopy. Then, standard E. coli O157:H7 strain ATCC 43888 was used to evaluate the bioactivity of zp39. A double dilution method was applied to investigate its efficacy in normal broth medium, serum, and highly saline conditions. Its effects on cell membrane permeability and potential were measured by fluorescent assays. Thereafter, morphological changes of E. coli O157:H7 cells were monitored by electron microscopy technologies. Finally, the potential application of zp39 in controlling EHEC in food was tested with spinach juice and the Galleria mellonella larvae model was employed to assess the in vivo efficacy. Results: Peptide zp39 presented an amphiphilic helical structure. It effectively inhibited the growth of E. coli O157:H7 at a concentration of 4 μmol/L in a bactericidal mode. Mechanistic studies revealed that it affected membrane permeability and potential in a dose-dependent manner. Moreover, zp39 maintained satisfactory bioactivity against E. coli O157:H7 even in the presence of 70% serum or 1,000 μmol/L chloride salts. In spinach juice application, > 90% E. coli O157:H7 cells were killed within 2 h after exposure to 64 μmol/L zp39. In vivo study proved that treatment with 64 μmol/L zp39 could effectively boost the survival ratio of infected larvae by 50%. Conclusions: This study depicts a synthetic dodecapeptide that shows the potential application in controlling EHEC. This molecule may be developed into a highly effective antimicrobial agent applied to prevent food contamination and associated infections.

Nanostructured multilayer CAE-PVD coatings based on transition metal nitrides on Ti6Al4V alloy for biomedical applications

Titanium alloys possess poor resistance to friction and this adversely affects the corrosion behavior and osseointegration of the implants made from these alloys. Nanostructured PVD coatings with biocompatibility, anti-wear and anti-corrosion characteristics have attracted much attention in biomedical applications. In this study, TiN and ZrN single layer and CrN/TiN and CrN/ZrN nanostructured multilayer thin films were applied on a Ti6Al4V substrate by means of cathodic arc PVD technique. The physical-chemical characterization of the coatings was conducted using FE-SEM, EDS, and XRD analyses. Their surface topography and wettability were measured. In addition, the hardness and adhesion strength were evaluated by means of Knoop microhardness and scratch tests, respectively. Also, the apatite-forming ability of the coatings was investigated through SEM, EDS and, FTIR. The corrosion performance of the coatings was studied using PDP and EIS assessments in SBF solution. According to the findings, the multilayer coatings have higher hardness and scratch resistance than single layers. The coating delamination tacked place in Lc equal 39.6 (N) and 39.3 (N) for CrN/TiN and CrN/ZrN coatings, respectively. The corrosion assessments revealed that the CrN/ZrN multilayer coating exhibited the best corrosion resistance due to its smoother surface and more dense structure in addition to its specific architecture. The ZrN single layer and CrN/ZrN multilayer coatings showed a better hydroxyapatite precipitation; however, all surfaces had satisfactory bioactivity. In all, this study showed that CrN/ZrN nanostructured multilayer thin film is potentially suitable candidate for orthopedic and dental implants.

Silicocarnotite: Novel Silicate Bioceramic With Osteogenic Property for Repairing Rat Cranial Critical-Sized Bone Defects

Critical-sized bone defects are an intractable orthopedic disease which often fails to regenerate spontaneously and requires additional intervention. Current therapies, including autografts and allografts, are not always satisfactory. Herein, the novel calcium phosphate bioceramic-containing silicon (CPS) with a carnotite structure was synthesized. In the present study, CPS was prepared for investigating the biocompatibility and bioactivity in vitro and in vivo in comparison to hydroxyapatite (HA). Our results showed that CPS bioceramics had favorable biocompatibility and rBMSCs could adhere on the surface well in vitro. Moreover, CPS could promote osteogenic differentiation of rBMSCs and the expression of osteogenic differentiation marker genes, including ALP, Runx-2, BSP, OCN, and OPN. In vivo, the results of micro-CT, histomorphometry, and histology analyses showed that CPS significantly enhanced critical-sized calvarial defects healing compared with HA. Overall, the present study demonstrated that CPS bioceramics had satisfactory bioactivities and osteogenic capacities, which could be a potential option for reconstructing critical-sized bone defects.

Biosynthesis of Fungal Natural Products Involving Two Separate Pathway Crosstalk

Fungal natural products (NPs) usually possess complicated structures, exhibit satisfactory bioactivities, and are an outstanding source of drug leads, such as the cholesterol-lowering drug lovastatin and the immunosuppressive drug mycophenolic acid. The fungal NPs biosynthetic genes are always arranged within one single biosynthetic gene cluster (BGC). However, a rare but fascinating phenomenon that a crosstalk between two separate BGCs is indispensable to some fungal dimeric NPs biosynthesis has attracted increasing attention. The hybridization of two separate BGCs not only increases the structural complexity and chemical diversity of fungal NPs, but also expands the scope of bioactivities. More importantly, the underlying mechanism for this hybridization process is poorly understood and needs further exploration, especially the determination of BGCs for each building block construction and the identification of enzyme(s) catalyzing the two biosynthetic precursors coupling processes such as Diels–Alder cycloaddition and Michael addition. In this review, we summarized the fungal NPs produced by functional crosstalk of two discrete BGCs, and highlighted their biosynthetic processes, which might shed new light on genome mining for fungal NPs with unprecedented frameworks, and provide valuable insights into the investigation of mysterious biosynthetic mechanisms of fungal dimeric NPs which are constructed by collaboration of two separate BGCs.

Effective and Sustained Control of Soil-Borne Plant Diseases by Biodegradable Polyhydroxybutyrate Mulch Films Embedded with Fungicide of Prothioconazole.

Soil-borne diseases and plant rhizosphere nematode have caused many crop yield losses. Increased environmental awareness is leading to more restrictions on the use of certain fumigants and root irrigation methods due to their impact on human health and soil system. Therefore, it is necessary to find alternative treatments to maintain crop economic yields and environmental sustainability. In the present work, biodegradable antifungal mulches were prepared by blending poly(3-hydroxybutyrate-co-4-hydroxybutyrate) (PHB) with fungicide of prothioconazole (PRO), which were used for effective and sustained control of soil-borne plant diseases. To reveal the application prospect of the PHB/PRO composite films in the management of soilborne plant diseases, some physical and biological properties were evaluated. The proper mulch film of PHB/PRO was assessed based on its mechanical and optical properties, while water solubility and the film micromorphology was further characterized. The release patterns of composite films under different pH levels were investigated. Moreover, the in vitro antifungal bioassay and pot experiment showed satisfactory bioactivity of the PHB/PRO films against Sclerotium rolfsii Sacc., a soil-borne disease in peanut fields. This study demonstrated that the biodegradable mulch films containing PRO fungicide are capable of inhibiting soil-borne plant pathogenic fungi effectively, and this facile but powerful strategy may find wide applicability in sustainable plant and horticulture protection.

Synthesis, Characterization, Theoretical Studies, and Antimicrobial/Antitumor Potencies of Salen and Salen/Imidazole Complexes of Co (II), Ni (II), Cu (II), Cd (II), Al (III) and La (III)

Although salens and imidazoles are well‐studied motifs among bioactive and therapeutic agents, their properties when combined in transition metal complexes are not well developed. To explore the structure/reactivity of this class of compounds, a salen‐based ligand, namely (2,2′‐{1,2‐ethanediylbis[nitrilo(E)methylylidene]}diphenol, S), and its binary (MS) and ternary (MSI) complexes (I = imidazole; M = Co (II), Ni (II), Cu (II), Cd (II), Al (III), and La (III)) have been synthesized and fully characterized by standard physicochemical and theoretical methods. Evidence from structural analysis tools along with DFT modeling revealed an unusual monobasic tridentate salen binding mode, involving the phenolic oxygen, the nitrogen of the azomethine group, and NH group formed via phenol‐to‐cyclohexadienone tautomerization, giving rise to a general molecular formula of MSI complexes as [M(S)(I)2(Cl)] for M (II) = Co, Ni, Cu and Cd or [M(S)(I)(Cl)2] for M (III) = Al and La, respectively. The antimicrobial activities of S, MS, and MSI were screened against several bacterial and fungal strains. Of all tested complexes, CdS and CuSI were the most effective antimicrobials, giving larger inhibition zones than the reference antibiotics. The antimicrobial efficacy for the MS complexes follows the order: CdS > gentamicin > CuS > NiS > CoS > LaS > AlS > S, whereas MSI complex, potencies are ordered as CuSI > gentamicin > CdSI >NiSI > CoSI > LaSI > AlSI > S. In vitro cytotoxicity screening of MSI complexes disclosed that both CuSI and CdSI exhibited higher activity against human liver (Hep‐G2) and breast (MDA‐MB231) carcinoma cell lines than the reference (cisplatin) drug. The satisfactory bioactivities observed for several of these compounds supports the underlying design idea for combining important bioactive motifs for possible therapeutic benefit.

Functionalization of a clustered TiO2 nanotubular surface with platelet derived growth factor-BB covalent modification enhances osteogenic differentiation of bone marrow mesenchymal stem cells

A multitude of micro- and nano-surface structures have been developed to improve the clinical performance of endosseous titanium (Ti) implants. However, most of these surface structures only simulate the topographic elements on a micro- or nano-scale. In this study, a nano-micro hierarchical TiO2 clustered nanotubular structure was fabricated using anodization, and then functionalized with platelet derived growth factor-BB (PDGF-BB) using PhoA (11-hydroxyundecylphosphonic acid)/CDI (carbonyldiimidazole) chemistry. The resulting 3-dimensional spatial biomimetic structure, named NTPCP, exhibited negligible cytotoxicity and satisfactory bio-activity for host cells, and significantly enhanced the attachment as well as osteogenesis-related functions (early-stage proliferation, extracellular matrix synthesis and mineralization) of human bone marrow mesenchymal stem cells (bMSCs). We observed drastically elevated expression of osteocalcin (OCN), which mirrored prominent bone formation around the NTPCP implants in a rat model. This study establishes a novel strategy to improve the osseointegration of endosseous Ti implants via surface nano-topographic modification and bio-factor covalent functionalization.

Preparation of starch derivatives bearing urea groups and the evaluation of antioxidant, antifungal, and antibacterial activities

Several starch derivatives bearing urea groups (TUCAST, MTUCAST, and PTUCAST) based on 6-O-chloroacetylated starch (CAST) were successfully designed and synthesized. FT-IR, 1H NMR spectroscopy, and elemental analysis were carried out to identify the structural characteristics of starch derivatives. The antioxidant activity of starch derivatives was tested by superoxide-radical scavenging and hydroxyl-radical scavenging assays. Their antifungal activity against Fusarium oxysporum f. sp. cucumebrium Owen, Phomopsis asparagus, and Fusarium oxysporum f. sp. niveum was estimated by hyphal measurement. Furthermore, the antibacterial activity against Escherichia coli and Staphylococcus aureus was evaluated by optical density method. Compared to starch, the products bearing urea groups showed enhanced antifungal action as well as an excellent antioxidant and antibacterial activities. Their bioactivities decreased roughly in the order of PTUCAST > MTUCAST > TUCAST > CAST > starch, which matched with the electron-withdrawing property of the different substituted groups of urea. Besides, the cytotoxic activity of starch and synthesized derivatives against L929 cells was evaluated using CCK-8 assay in vitro and all samples showed weak cytotoxicity. The results suggested that these novel starch derivatives possessing satisfactory bioactivities could be widely used in the food industry.

Facile one-step bioinspired mineralization by chitosan functionalized with graphene oxide to activate bone endogenous regeneration

Facilitated endogenous tissue engineering is emerging as a convenient and easy strategy for bone repair. However, the substitution with satisfactory bioactivity and osteoinductivity which can activate endogenous stem cells responds and in situ recruit them homing towards to damaged area remains a challenge. To stimulate the biomineralization process of inorganic nanoparticles in natural bone, bioactive nano hydroxyapatite particles (nHAP) were in situ crystallized into the graphene oxide/chitosan/nHAP (GO/CS/nHAP) scaffold via effective regulation of CS functionalized with GO network matrix and presented a uniform dispersion with nanometer-scale. As-prepared scaffold exhibited better physicochemical properties, such as three-dimensional (3D) porous bone-like hierarchical structure, proper mechanical property, biodegradation as well as suitable water uptake and retention ratio. The biomimetic mineralization and cell culture experiments demonstrated that hybrid scaffold possessed superior bioactivity and cell proliferation ability in vitro. In addition, the rat calvarial defect repair models and tissue pathological characterization further proved that the hybrid scaffold had excellent biocompatibility and capacity of in situ inducing bone regeneration. Herein, the prepared scaffold might be an excellent candidate for endogenous bone repair.

Microstructural investigation of porous titanium coatings, produced by thermal spraying techniques, using plasma atomization and hydride-dehydride powders, for orthopedic implants

The present study focuses on porous titanium (commercially pure Ti) coatings for future use on medical implants, manufactured by specific thermal spray method. Its objective is to investigate the possibility of Ti porosity to offer room for medication storage in addition to bone growth promotion. Three specimens for each different type of coating were produced by different sets of thermal spray process/feedstock powder, namely, (1) Flame Spray (FS) with spherical Plasma Atomization (PA) powder, (2) Atmospheric Plasma Spray (APS) with spherical PA powder and (3) APS with angular Hydride – Dehydride (HDH) powder. The specific types of specimens along with the two powders produced by the PA and HDH processes were characterized using various techniques, namely (a) Roughness measurements of the coated surfaces and thickness measurements of the coatings, which disclosed the highest values for the FS-PA coating, Ra = 11.19 ± 0.21 μm and average thickness of 281 μm, (b) Optical microscopy and SEM-EDS to study the surface morphology and microstructure of the coatings and discover any possible oxidation or other phases. The porosity percentage was measured and the pore size distribution was also estimated. The porosity percentages of the coatings ranged from 12% on the APS-PA coating to 34% on the FS-PA coating, (c) XRD analyses which showed varying titanium oxide formations for each type of specimen. These oxides may prove to be beneficial for the development of osseous tissue, (d) assessment of biological response of the coatings in vitro that resulted in satisfactory primary response in a physiological environment and the formation of calcium phosphate phases with Ca/P ratio of 1.61 and (e) Vickers microhardness measurements, which resulted in values that fluctuated from 786.6 for the FS-PA coating to 967.6 for the APS-HDH coating. Overall, the produced FS-PA coating is characterized by high porosity content and satisfactory bioactivity, in order to fulfill the objective of the project for biomolecule incorporation and drug storage.

Effective recovery of trans-resveratrol from the leaching solution of muscat grape pomace by developing a novel technology of foam fractionation

Resveratrol (2,5,4′-trihydroxystilbene) is a naturally occurring phytoalexin produced by some spermatogphytes and it has recently attracted the increasing attention of agronomists and pharmacologists owing to its satisfactory bioactivities. The objective of this work was to develop a cost-effective technology of foam fractionation to recover trans-resveratrol (trans-Res) from the leaching solution of muscat grape pomace on the assistance of molecular imprinting modified SiO2 nanoparticles. First, trans-Res was leached from muscat grape pomace through the method of alkaline extraction. Under the suitable leaching conditions, the leaching yield of trans-Res reached 84.34%. Adsorption experiments were performed for describing the adsorption behavior of trans-Res on the molecular imprinting modified SiO2 nanoparticles. Results indicated that their adsorption could be fairly described by Freundlich model and fitted well with the pseudo-second-order kinetics model. Moreover, the molecular imprinting modified SiO2 nanoparticles could effectively maintain the stability of trans-Res through avoiding the cis-trans photo-isomerization and oxidative degradation. Finally, foam fractionation was carried out for recovering trans-Res from the leaching solution, in which the concentration of trans-Res was as high as 29.09 mg/L. The molecular imprinting modified SiO2 nanoparticles were used as the collector. Under the suitable conditions of loading liquid volume 250 mL, particle size of molecular imprinting modified SiO2 nanoparticles 436.0 nm, sapindus saponin concentration 0.075 g/L, volumetric gas flow rate 100 mL/min and pore diameter of gas distributor 0.180 mm, the enrichment ratio and the recovery percentage of trans-Res reached 13.68 ± 1.03 and 89.73 ± 3.57%, respectively. This work is expected to provide a new technology for selectively recovering non-surface-active materials from the solution with their isomers or analogues, and to facilitate the industrialization of foam fractionation.

Investigating the affinity of BDE154 and 3OH-BDE154 with HSA: Experimental and simulation validation.

The physicochemical properties of polybrominated diphenyl ethers are important for modeling their transport, but these data are often missing. Here, satisfactory bioactivity results were obtained using human serum albumin as the carrier, 2,2',4,4',5,6'-hexabromodiphenyl ether (BDE154) and 3-hydroxy-2,2',4,4', 5,6'-hexabromodiphenyl ether (3OH-BDE154) as the ligands, using UV-visible absorbance, fluorescence, circular dichroism, molecular docking, and molecular dynamics methods. The interactions between human serum albumin and BDE154 or 3OH-BDE154 were verified, consistent with the static quenching procedure. At pH 7.4, the binding constants of the complexes for site I were relatively comparable and increased in the order BDE154<3OH-BDE154. Then, the secondary structure and kinetic parameters of albumin were analyzed using the circular dichroism spectra and GROMACS software. The data obtained from these simulations indicate that hydrophobic attraction might be the key factor for the stability of complexes. The docking experiments provided further insight into the hydrophobic pocket and showed that 3OH-BDE154 has a stronger binding affinity to human serum albumin than BDE154. The experimental spectral data were obtained and compared with the simulation results, showing good agreement. A detailed analysis of PBDEs-HSA interactions would provide valuable information to better understand the interaction on this class of compounds.

Biocompatibility of ultrafine grained zircaloy-2 produced by cryorolling for medical applications.

The present work deals with development of ultrafine grained zircaloy-2 and studying its potential for orthopedic application. The multimodal structure, i.e. the combination of coarse, ultrafine grained (UFG) and nanograined structures of zircaloy-2 is obtained by cryorolling the bulk alloy followed by annealing at 400 °C, and 450 °C for 30 min. An estimation of surface wettability of the alloy was obtained through contact angle measurement. The bioactivity of the alloy samples was investigated by incubating bone marrow derived stem cells. The cellular attachment, adhesion and proliferation at different intervals of incubation were characterized by scanning fluorescent microscopy and MTT assay. Cell culture results indicated that liquid nitrogen rolled alloy samples exhibited excellent in-vitro biocompatibility together with satisfactory bioactivity. Excellent genomic expressions were observed for zircaloy 2 processed by cryorolling.

Collagen II/Hyaluronan/Chondroitin-6-Sulfate Tri-copolymer Scaffold for Nucleus Pulposus Tissue Engineering

Introduction This study aims to investigate the bioactivity of collagen II/hyaluronan/chondroitin-6-sulfate tri-copolymer as bionic scaffold for nucleus pulposus (NP) tissue engineering. Materials and Methods Collagen II (C II) (pH 1-2) was mixed with hyaluronan (HyA) and lyophilized to prepare C II/HyA matrices. Chondroitin 6-sulfate (6-CS) was covalently attached to the C II/HyA matrices using 1-ethyl-3-(3-dimethyl aminopropyl) carbodiimide (EDC) and N-hydroxysuccinimide (NHS). Then, cells were expanded from rabbit NP and seeded in the tri-copolymer scaffold. Cell-scaffold hybrids were maintained for up to 28 days in culture. Cell viability/proliferation, extracellular matrix (ECM)-related gene expression, and the content of sulfated glycosaminoglycans (s-GAG) were evaluated. Results When cultured for 28 days, the cell-scaffold hybrids maintained active cell viability/proliferation and exhibited a significantly increased s-GAG content. In addition, rabbit NP cells cultured in the scaffold demonstrated a significantly higher level of C II and aggrecan gene expression and a significantly lower level of Collagen I (C I) gene expression when compared with that of monolayer cells. Histological studies and scanning electron microscopy (SEM) further indicated newly secreted ECM deposits in the scaffolds. Conclusion In conclusion, the C II/HyA-CS scaffold may be an alternative material for NP tissue engineering due to its satisfactory bioactivity, and it deserves further in vivo investigation. Disclosure of Interest None declared

Expression and Purification of Bioactive High-Purity Recombinant Mouse SPP1 in Escherichia coli

Secreted phosphoprotein 1 (SPP1) is a phosphorylated acidic glycoprotein. It is broadly expressed in a variety of tissues, and it is involved in a number of physiological and pathological events, including cancer metastasis, tissues remodeling, pro-inflammation regulation, and cell survival. SPP1 has shown its function of protecting tissues and organs against injury and wound, giving itself potentials to become a therapy target or giving its antibodies of other counter-acting reagents potentials to become drug candidates. Non-tagged (native) recombinant SPP1 would be valuable in therapeutic and pharmaceutical researches. In our study, mouse Spp1 DNA fragment without signal peptide was built in pET28a(+) vector and transformed into Escherichia coli BL21 (DE3). The recombinant mouse SPP1 (rmSPP1) was then expressed in bacteria upon induction by isopropyl β-D-thiogalactopyranoside (IPTG). The abundance of rmSPP1 was increased using isoelectric precipitation and ammonium sulfate fractionation methods, and anion and cation exchange chromatography was employed to further purify rmSPP1. Finally, we got rmSPP1 product with 12.8 % productivity, 97 % purity, satisfactory bioactivity, and low endotoxin content.

What are the ideal properties for functional food peptides with antihypertensive effect? A computational peptidology approach

Peptides with antihypertensive potency have long been attractive to the medical and food communities. However, serving as food additives, rather than therapeutic agents, peptides should have a good taste. In the present study, we explore the intrinsic relationship between the angiotensin I-converting enzyme (ACE) inhibition and bitterness of short peptides in the framework of computational peptidology, attempting to find out the appropriate properties for functional food peptides with satisfactory bioactivities. As might be expected, quantitative structure–activity relationship modeling reveals a significant positive correlation between the ACE inhibition and bitterness of dipeptides, but this correlation is quite modest for tripeptides and, particularly, tetrapeptides. Moreover, quantum mechanics/molecular mechanics analysis of the structural basis and energetic profile involved in ACE–peptide complexes unravels that peptides of up to 4 amino acids long are sufficient to have efficient binding to ACE, and more additional residues do not bring with substantial enhance in their ACE-binding affinity and, thus, antihypertensive capability. All of above, it is coming together to suggest that the tripeptides and tetrapeptides could be considered as ideal candidates for seeking potential functional food additives with both high antihypertensive activity and low bitterness.

In vivo biocompatibility and bioactivity of in situ synthesized hydroxyapatite/polyetheretherketone composite materials

AbstractHydroxyapatite/polyetheretherketone (HA/PEEK) composite materials were prepared via an in situ synthesis process in order to achieve strong bonding between PEEK matrix and hydroxyapatite fillers, and ultimately to improve the mechanical properties of the composites. In the study, the biocompatibility of the synthesized HA/PEEK materials was investigated by acute toxicity test, hemolytic test, sensitization test, pyrogen test, intradermal test, and toxicity assay test on animal tissue and cells for the purpose of examining the possible adverse effects of the residue organic chemicals from the in situ synthesis process. In vivo bioactivity of both lab‐synthesized PEEK and HA/PEEK composites with various HA content was also studied. It is found that the in situ synthesized composite materials possess good biocompability without toxicity. Although the bioactivity of the material increases with HA content, the composite material with 5.6 vol % HA exhibits satisfactory bioactivity without compromising its excellent mechanical performance, which hints to a potential use as load‐bearing orthopedic material. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013