A double-layer cellulose/pectin-soy protein isolate-pomegranate peel extract micro/nanofiber dressing for acceleration of wound healing.

Multi-layered wound dressings can closely mimic the hierarchical structure of the skin. Herein, a double-layer dressing material is fabricated through electrospinning, comprised of a nanofibrous structure as a healing-support layer or the bottom layer (BL) containing pectin (Pec), soy protein isolate (SPI), pomegranate peel extract (P), and a cellulose (Cel) microfiber layer as a protective/monitoring layer or top layer (TL). The formation of a fine bilayer structure was confirmed using scanning electron microscopy. Cel/Pec-SPI-P dressing showed a 60.05 % weight loss during 7 days of immersion in phosphate buffered solution. The ultimate tensile strength, elastic modulus, and elongation at break for different dressings were within the range of 3.14-3.57 MPa, 32.26-36.58 MPa, and 59.04-63.19 %, respectively. The release of SPI and phenolic compounds from dressings were measured and their antibacterial activity was evaluated. The fabricated dressing was non-cytotoxic following exposure to human keratinocyte cells. The Cel/Pec-SPI-P dressing exhibited excellent cell adhesion and migration as well as angiogenesis. More importantly, in vivo experiments on Cel/Pec-SPI-P dressings showed faster epidermal layer formation, blood vessel generation, collagen deposition, and a faster wound healing rate. Overall, it is anticipated that the Cel/Pec-SPI-P bilayer dressing facilitates wound treatment and can be a promising approach for clinical use.

Mupirocin loaded core-shell pluronic-pectin-keratin nanofibers improve human keratinocytes behavior, angiogenic activity and wound healing.

In the current study, a core-shell nanofibrous wound dressing based on Pluronic-F127 (F127) containing 2 wt% mupirocin (Mup) core and pectin (Pec)-keratin (Kr) shell was fabricated through coaxial electrospinning technique, and the blended nanofibers were also fabricated from the same materials. The fiber diameter and specific surface area of the blended nanofibers were about 101.56 nm and 20.16 m2/g, while for core-shell nanofibers they were about 97.32 nm and 25.26 m2/g, respectively. The resultant blended and core-shell nanofibers experienced a degradation of 27.65 % and 32.28 % during 7 days, respectively. The drug release profile of core-shell nanofibers revealed a sustained release of Mup over 7 days (87.66 %), while the blended F127-Pec-Kr-Mup nanofibers had a burst release within the first few hours (89.38 % up to 48 h) and a cumulative release of 91.36 % after 7 days. Due to the controlled release of Mup, the core-shell structure significantly improved the human keratinocytes behavior, angiogenic potential and wound healing in a rat model compared to the blended structure. In conclusion, the F127-Mup/Pec-Kr core-shell nanofibrous wound dressing appears to be a promising candidate for the prevention of infection, and can potentially accelerate the recovery and healing of chronic and ischemic wounds.

Antibacterial and Virucidal Evaluation of Ultrafine Wire Arc Sprayed German Silver Coatings.

Copper and its alloys are known as antimicrobial agents that can be used in public places; however, pure copper has a low wear resistance and tends to lose its gloss relatively fast and stainless steel is still more desirable because of its mechanical properties and stable appearance. In this research, German silver coatings, a copper-nickel alloy, are studied as a superior alternative for pure copper coatings. German silver coating on mild steel substrates and stainless steel with two different surface roughnesses was prepared and placed into water bath up to 6 months to investigate the corrosion and exposure effects on the antibacterial behavior. A range of techniques was used to study the microstructure, surface morphology and mechanical properties such as microhardness, coating bonding adhesion, surface roughness and wettability of the coating. Colony count method was used to measure the antibacterial properties, and samples were tested against influenza A virus to evaluate the virucidal activity. The coating thickness was around 130 µm and contained 15% pores and oxides with splats forming inside the coating structure. Inside each splat, columnar grains could be seen with an average of 700 nm width and 4 µm length. The bonding strength of the coating was about 15 MPa, the hardness of coatings was about 180 HV, and the average surface roughness of the as-sprayed samples was about 10 µm. German silver coatings can destroy both Staphylococcus aureus and Escherichia coli by more than 90% after 6 h of exposure time, and it also has a high-level of virucidal activity against influenza A virus after 2 h exposure time. Antibacterial behavior did not show any significant changes after 6 months of immersing samples in water bath. Thus, thermally sprayed German silver coatings exhibited silvery color for a long period of time, while its antimicrobial efficiency was comparable to pure copper coatings. Supplementary Information: The online version contains supplementary material available at 10.1007/s11666-022-01528-4.

Sodium-borohydride exfoliated bismuthene loaded with Mitomycin C for chemo-photo-radiotherapy of triple negative breast cancer.

In current study, a new remotely controlled drug delivery, radio-sensitizing, and photothermal therapy agent based on thioglycolic acid modified bismuth nanosheets is thoroughly evaluated. Bismuth nanosheets were synthesized using sodium borohydride (NaBH4) and Tween 20 through low energy (400 W) sonication within 2 h. The resultant nanosheets were 40-60 nm in size and 1-3 atomic layers in thickness. The morphological and structural characteristics of the nanosheets were studied using transmission electron microscopy, high-resolution transmission electron microscopy, X-ray diffraction, Raman spectroscopy and ultraviolet spectroscopy. The surface of the nanosheets was modified using thioglycolic acid, which resulted in enhanced Mitomycin C loading capacity to 274.35% and circumvented the burst drug release due to the improved electrostatic interactions. At pH 7.4 and 5.0, the drug release was significantly boosted from 45.1 to 69.8%, respectively. Thioglycolic acid modified bismuth nanosheets under 1064 nm laser irradiation possessed photothermal conversion efficiency of η=51.4% enabling a temperature rise of 24.9 °C at 100 µg/ml in 5 min. The combination of drug delivery, photothermal therapy, and radio-sensitization greatly damaged the MDA-MB-231 cells through apoptosis and diminished their colony forming.

Activated platelet-rich plasma improves cartilage regeneration using adipose stem cells encapsulated in a 3D alginate scaffold.

In the current study, the effect of superimposing platelet-rich plasma (PRP) on different culture mediums in a three-dimensional alginate scaffold encapsulated with adipose-derived mesenchymal stem cells for cartilage tissue repair is reported. The three-dimensional alginate scaffolds with co-administration of PRP and/or chondrogenic supplements had a significant effect on the differentiation of adipose mesenchymal stem cells into mature cartilage, as assessed by an evaluation of the expression of cartilage-related markers of Sox9, collagen II, aggrecan and collagen, and glycosaminoglycan assays. For in vivo studies, following induction of osteochondral lesion in a rabbit model, a high degree of tissue regeneration in the alginate plus cell group (treated with PRP plus chondrogenic medium) compared with other groups of cell-free alginate and untreated groups (control) were observed. After 8 weeks, in the alginate plus cell group, functional chondrocytes were observed, which produced immature matrix, and by 16 weeks, the matrix and hyaline-like cartilage became completely homogeneous and integrated with the natural surrounding cartilage in the defect site. Similar effect was also observed in the subchondral bone. The cell-free scaffolds formed fibrocartilage tissue, and the untreated group did not form a continuous cartilage over the defect by 16 weeks.

Monodispersed bioactive glass submicron particles and their effect on bone marrow and adipose tissue-derived stem cells.

Spherical monodispersed bioactive particles are potential candidates for nanocomposite synthesis or as injectable particles that could be internalized by cells for the local sustained delivery of inorganic therapeutic ions (e.g., calcium or strontium). Particles are also likely to be released from porous bioactive glass and sol-gel hybrid scaffolds as they degrade; thus, it is vital to investigate their interaction with cells. Spherical monodispersed bioactive glass particles (mono-SMBG), with diameters of 215 ± 20 nm are synthesized using a modified Stöber process. Confocal and transmission electron microscopy demonstrate that mono-SMBGs are internalized by human bone marrow (MSCs) and adipose-derived stem cells (ADSCs) and located within cell vesicles and in the cytoplasm. Particle dissolution inside the cells is observed. Alamar Blue, MTT and Cyquant assays demonstrate that 50 µg mL(-1) of mono-SMBGs did not inhibit significantly MSC or ADSC metabolic activity. However, at higher concentrations (100 and 200 µg mL(-1)) small decrease in metabolic activity and total DNA is observed. Mono-SMBG did not induce ALPase activity, an early marker of osteogenic differentiation, without osteogenic supplements; however, in their presence osteogenic differentiation is achieved. Additionally, large numbers of particles are internalized by the cells but have little effect on cell behavior.