In vitro cytotoxicity of monticellite based bioactive ceramic powder synthesized from boron derivative waste

The cytotoxicity of monticellite based bioactive ceramic powder, which was synthesized from boron derivative waste has been determined by in vitro assays of MTT, NRU, and JC-1 staining. The toxicity of powder on different mammalian cell lines (3T3-L1, HUVEC, CRL-2120) was evaluated at the concentrations of 10, 100, 200, 400 and 800?µg/mL to justify its potential for biomedical applications. The obtained results showed that monticellite based bioactive ceramic powder possesses not only bioactive feature but also biocompatible characteristic at the concentration range of 10–200?µg/mL. Hence, monticellite based bioactive ceramics have high potential as a bone graft substitute for bone void filling and coating applications.     

Prediction and comparison of textural properties of magnetic copolymer supports for enzyme immobilization

Magnetic polymers supports have proven to be valuable materials for enzyme immobilization, as they allow recovering the catalyst by magnetic separation, precluding the need for costly and time-consuming separation steps. In this study, magnetic copolymer supports were synthesized using styrene (STY) and different crosslinking agents (divinylbenzene, ethylene glycol dimethacrylate, or triethylene glycol dimethacrylate) and initiators (azobisisobutyronitrile or benzoyl peroxide) and used to immobilize Candida antarctica lipase B (CALB). The aim was to obtain biocatalysts with high enzymatic activity and satisfactory morphological properties for use in biotransformation reactions. Two morphological properties known to influence the immobilization yield were taken into consideration, specific surface area, and swelling index. Experimental data were compared to the predictions of a model based on molar balance, method of moments, numerical fractionation, and elementary gel structures. The high correlation (R² = 0.9974) between experimental and predicted values demonstrated the suitability of the model for estimating the textural properties of enzyme supports. CALB was successfully immobilized, showing high hydrolytic activity (500–700 U g⁻¹) and good thermal stability at 50°C. CALB/STY-EGDMA-M was 14 times more stable than free CALB. The results confirm the efficiency of the immobilization method and the suitability of the copolymers for enzyme immobilization.     

Antimicrobial and Anticancer Properties of Synthetic Peptides Derived from the Wasp Parachartergus fraternus

Agelaia-MPI and protonectin are antimicrobial peptides isolated from the wasp Parachartergus fraternus that show antimicrobial and neuroactive activities. Previously, two analogues of these peptides, neuroVAL and protonectin-F, were designed to reduce nonspecific toxicity and improve potency. Here, the three-dimensional structures of neuroVAL, protonectin and protonectin-F were determined by using circular dichroism and NMR spectroscopy. Antibacterial, antifungal, cytotoxic and hemolytic activities were tested for the parent peptides and analogues. All peptides showed moderate antimicrobial activity against Gram-positive bacteria, with agelaia-MPI being the most active. Protonectin and protonectin-F were found to be toxic to cancerous and noncancerous cell lines. Internalization experiments revealed that these peptides accumulate inside both cell types. By contrast, neuroVAL was nontoxic to all tested cells and was able to enter cells without accumulating. In summary, neuroVAL has potential as a nontoxic cell-penetrating peptide, while protonectin-F needs further modification to realize its potential as an antitumor peptide.     

Aloe vera-based antibacterial porous sponges for wound dressing applications

Journal of Porous Materials - The antibacterial sponges with high macroporosity, high interconnectivity and high biocompatibility is a significant concern for wound healing applications. In this...     

Fabrication and characterization of in-situ Al3Ni intermetallic and CeO2 particulate-reinforced aluminum matrix composites

Al-xNi-yCeO₂ (x = 6, 10, 15, 20 and y = 0, 5, 10 wt%) composites were produced by a powder metallurgical production route. Powder mixtures of Al, Ni and CeO₂ were fabricated via mechanical alloying (MA) for 4 h in a Spex-type high-energy ball mill. Both the mechanically alloyed (MAed) and non-MAed (as-blended mixtures) powders were pre-compacted in a hydraulic press under 650 MPa and then pressurelessly consolidated at 630 °C for 2 h under an inert atmosphere. The effects of MA process and the amounts of Ni and CeO₂ on the microstructural, mechanical and tribological properties of the sintered composites were determined. Based on the SEM and XRD investigations, the MAed powders illustrated a homogenous structure, comprising flaky particles with smaller crystallite sizes and greater lattice strain. According to the XRD analysis, Ni formed Al–Ni intermetallic compounds in the matrix of sintered composites that act as secondary reinforcement phases. The SEM observations conducted on the MAed samples demonstrated more uniformly and finely distributed Al₃Ni and CeO₂ phases in the microstructure of the MAed samples, unlike the non-MAed ones. The hardness values of sintered composites increased due to the MA process and increasing Ni and CeO₂ amounts, and the hardness value of the MAed Al20Ni–10CeO₂ sample reached 179 HV. The ultimate compressive strength and failure strain of the MAed Al6Ni–10CeO₂ sample were 441 MPa and 11.3%. In the Al20Ni–10CeO₂ sample, the compressive strength and failure strain were 391 MPa and 5.5%, respectively. Additionally, the reciprocating wear test results illustrated that both wear resistance and hardness values of the composites increased as the amounts of Ni and CeO₂ increased, and the Al20Ni–10CeO₂ sample exhibited the highest wear resistance as 0.175 × 10^-3 mm³/Nm.     

Structural and histological observations on the male reproductive system of adult red poplar leaf beetle Chrysomela populi Linnaeus, 1758 (Coleoptera: Chrysomelidae)

This study described the anatomy and histology of the male reproductive system in Chrysomela populi, which is an economically important species belonging to the family Chrysomelidae. Therefore, reproductive biology has been studied to combat this insect. As well as, the characters associated with the reproductive tract have been potential to discuss aspects of the system and to better understand the reproductive dynamics. The male reproductive system of C. populi has a pair of testes, a pair of vas efferentia and deferentia, a pair of seminal vesicles, a pair of accessory glands, an ejaculatory bulb, an ejaculatory duct, and an aedeagus. The testis consists of two flower-shaped lobes. Each testis has 20 sperm tubules (testicular follicles) containing cysts of germ cells at various developmental stages within the light orange peritoneal sheath. Testicular follicles are composed of three different (growth, maturation, and differentiation) zones. In the middle region of each testis joins with the vas efferens. The testis is attached to the seminal vesicle by a small stalk like vas efferens. In the lumen of the vas efferens, seminal vesicle, and vas deferens, sperms form clumps in the form of thin threads. The proximal end of the vas deferens is connected to the common ejaculatory duct. It joins with the ejaculatory bulb. Around the ejaculator bulb, there is a pair of convoluted, flat-surface tubular structure accessory glands. Posterior ejaculatory duct joins with the aedeagus.     

Microstructural,mechanical and tribological properties of suspension plasma sprayed YSZ/h-BN composite coating

Brittleness, relative high friction coefficient and wear rate limit the applications of ceramic coatings as wear-resistant layers. However, because embedding additives with ceramic matrix has demonstrated to be an effective way to improve coating performances, different contents and size of h-BN were added into an YSZ suspension. Afterwards, the YSZ/h-BN composite coatings were manufactured by suspension plasma spray and their tribological analysis indicated that: i) the reduction of the friction coefficient and wear rate can be achieved by incorporating h-BN into YSZ coating. ii) finer h-BN particle is more helpful to enhance the tribological properties of the coating. iii) the optimum content is dependent on h-BN particle sizes. iv) when the contents and the size of the h-BN inclusion increase, the probability distribution of the micro-hardness can become bi-modal. Three worn surface conditions were summarized and their wear mechanisms were discussed as well.