Keratin, a versatile polymer rich in cysteine and disulfide bonds, exhibits strength and elasticity, making it crucial for tissue engineering. Its biocompatibility and biodegradability foster the development of advanced biomaterials. Incorporating medicinal plant extracts enhances keratin's therapeutic potential. Additionally, green-synthesized silver nanoparticles (AgNPs) provide antimicrobial properties. Electrospun keratin-based mats may be promising materials for medical applications since electrospinning enables the fabrication of nanofibrous scaffolds with high surface area-to-volume ratios, mimicking the extracellular matrix's structure. This research aims to develop electrospun keratin mats enhanced with medical plants and green-synthesized AgNPs for medical dressings.

To prepare keratin-based electrospun solutions keratin hydrolysate and polyethylene oxide (PEO) were used. Matricaria chamomilla as a medicinal plant for extract and AgNPs preparation and Sodium Alginate as an additive were chosen. The UV-Vis analysis was conducted to characterize the green-synthesized AgNPs. The structure of electrospun mats micro-nanofibers was analyzed by SEM.

The UV-Vis exhibited an absorption peak spanning 400-450 nm, indicating the presence of surface plasmon resonance characteristic of AgNPs. This observation confirms the successful synthesis of AgNPs.

Furthermore, the electrospun fibers displayed homogeneity. Analysis of fiber diameters revealed that 88% of keratin hydrolysate and PEO fibers fell within the 100-200 nm range. The addition of the herbal extract led to an increase in fiber diameters, with 50% of measured fibers ranging from 100-200 nm and 44% from 201-300 nm, while the incorporation of biosynthesized AgNPs had no significant impact on fiber diameters. The addition of Sodium Alginate (c=3 %) resulted in a notable increase in fiber diameters, with 84-95% of fibers falling within the 100-300 nm range.

The findings indicate that keratin-based compositions enriched with M.chamomilla extract and green-synthesized AgNPs can be effectively electrospun. Incorporating Sodium Alginate enhances the versatility of the electrospun mats for medical applications. Nevertheless, further in-depth investigation is required.

Due to society's growing concern for the environment, there is an increasing demand for developing biomaterials in different industrial sectors. At the governmental level, the application of a circular economy is being promoted, based on the revaluation of by-products produced during manufacturing, which can serve as raw materials for the manufacture of other raw materials. In the past few years, chitosan has come into focus as a potential biomaterial for both the biomedical and food sectors, as it possesses inherent antibacterial and antifungal properties, antioxidant activity, good film-forming abilities, biocompatibility, non-antigenicity, and analgesic, anti-inflammatory and hemostatic activities. Chitosan is a biodegradable polycationic polysaccharide whose main components are glucosamine and N-acetylglucosamine monomers dispersed randomly and connected by β-1,4-glycosidic bonds (Du et al., 2024; Yin et al., 2024). This biopolymer has been studied in different forms, such as nanoemulsions, hydrogels, or composites, obtaining favorable results for its application in edible packaging to help extend the shelf life of perishable foods such as fruits and vegetables, as well as in biomedicine as a material that helps wound healing (Du et al., 2024; Gritsch et al., 2018; Káčerová et al., 2024). Thus, this systematic review aims to present the available information on the formation of antibacterial biomaterials from chitosan with potential applications in biomedicine and food packaging from a circular economy point of view, since this compound is highly present in the skeleton of crustaceans and is a by-product of the food industry.

A bioengineered bone marrow niche model to support long-term HSCs in vitro
Long-term reconstituting haematopoietic stem cells (LT-HSCs) are used to treat blood disorders via bone marrow transplantation to engraft and repopulate the blood system. The very low abundance of LT-HSCs and their rapid differentiation once removed from their niche in the bone marrow hinders their clinical utility. Previous developments using stromal feeder layers, defined media cocktails, and bioengineering have enabled HSC expansion in culture, but of mostly short-term HSCs (ST-HSC) and progenitor populations at the expense of naïve LT-HSCs. Here, we report the creation of a bioengineered LT-HSC maintenance niche that recreates physiological extracellular matrix organisation, using soft collagen type-I hydrogels to drive nestin expression in perivascular stromal cells (PerSCs or pericytes). We demonstrate that nestin, which is expressed by HSC-supportive bone marrow stromal cells, is cytoprotective and, via regulation of metabolism, is important for HIF-1α expression in PerSCs. When CD34+ve HSCs were added to the bioengineered niches comprising nestin/HIF-1α expressing PerSCs, LT-HSC numbers were maintained with normal clonal and in vivo reconstitution potential, without media supplementation. We provide proof-of-concept that our bioengineered niches can support the survival of CRISPR edited HSCs. Successful editing of LT-HSCs ex vivo can have potential impact on the treatment of blood disorders.

Anthracyclines are crucial in treating neoplastic diseases but can cause cardiomyopathy and brain damage. Rutin, a bioflavonoid, improves brain damage induced by doxorubicin but has limitations. Hybrid nanoparticles (H-NPs) were developed to enhance rutin's effectiveness and protect brain cells. The H-NPs were formulated using phosphatidylcholine, palmitoylethanolamide (PEA), cholesterol, poloxamers (LP and LPR) and hyaluronic acid (HA) (LPHA, LicpHA and LPHAR and LicpHAR) via the nanoprecipitation technique. PEA reduces inflammation, while HA aids in mucoadhesion and absorption enhancement. The mean size, stability size, zeta potential (ZP), morphology, thermal properties, encapsulation efficiency, drug content, and in vitro drug release and permeation were studied. The cellular uptake of LPP and LPH was investigated in cell lines. Cytotoxicity and anti-inflammatory activity were evaluated in cells. HA and PEA influenced the size of H-NPs. The mean size increased from 118 nm for LPP to 179 nm for LicpHA and further to 247 nm for LPHR. The size also increased after rutin loading, ranging from 171 nm for LPPR to 255 nm for LPHR. HA's addition influenced the ZP, shifting from -17.3 mV for LPP to -29.9 mV for LPH and finally to -35 mV for LicpHA. TEM images showed spherical shapes with irregular surfaces for all N-HPs. The total amount of rutin in the dispersion was approximately 97%, with an encapsulation efficiency of 68%. Thermal analysis indicated the presence of HA on the LPH surface. In vitro, studies demonstrated significantly improved drug permeation with both systems, higher than rutin-free solutions. LPP and LPH showed rapid cellular uptake within three hours. LPPR and LPHR significantly reduced cell death and induced inflammation. All H-NPs resulted in a greater anti-inflammatory effect compared to H-NPs without PEA.

In summary, LPH and LicpHA show potential for rutin encapsulation for different delivery routes. Additionally, rutin-loaded PEA H-NPs exhibit enhanced vasculoprotective effects.

1 Introduction

Noble metal nanoparticles (NPs), such as gold and silver, have been studied extensively in various scientific fields due to their peculiar properties. Researchers have used NPs to fabricate biosensors. The demand for biosensors for virus detection has increased, and research is focusing on ways to fabricate small, portable devices enabling rapid and accurate detection. İn this work, noble metal NPs of different shapes and sizes, including nanospheres, nanowires, nanocubes, and nanocylinders, were dispersed in surrounding media to simulate, using the discrete dipole approximation (DDA) method, their plasmonic properties. For this, a new model was proposed to calculate the response of the surface plasmon peaks of the NPs considered, and new analytical formulas were presented. The RISs of oxide-coated metal nanocubes were studied here, too. RISs were found to depend on the shape, size, core material, shell thickness, and shell composition of the NPs.

2 Methods

-DDA is a general technique for calculating the scattering and absorption of electromagnetic radiations by particles of arbitrary shapes and compositions.

-The polarizability of the NPs considered can be written as follows:

where V represents the volume of the NP. F defines the depolarization factor.

-The properties of the NPs considered are quantified, in this work, in terms of absorption (C_abs) and scattering (C_sca) cross-sections:

-Sensitivity is

3 Results

-A shift in plasmon wavelength with the shell thickness for X-SiO₂ (X= Au, Ag, and Al) was found.

-A shift in the peak wavelength with the refractive index of medium for coated metallic nanocubes was found.

-A variation in sensitivity with particle size was found.

4-Conclusion

A new model was proposed and developed to model and control the plasmon peak position and intensity according to the particle size, core material, shell thickness, and shell composition. The RIS factor increased with an increasing thickness of the oxide layer.

Over the past twenty years, the field of tissue engineering and regenerative medicine (TERM) has been significantly impacted by the emergence of 3D bioprinting technology. This advancement has enabled the precise printing of tissues composed of a single cell type, with remarkable resolution and fidelity. Nevertheless, achieving the desired functionality of tissues has remained a challenge due to the absence of diverse cell populations and variations in microenvironment distribution. Traditional 3D bioprinting methods have struggled to provide an effective approach for incorporating multiple cells and biomaterials in a controlled manner. The use of interchangeable syringe-based systems has often led to issues such as delamination between interfaces, particularly hindering the fabrication of interconnected constructs like cartilage and bone tissue. In this study, we introduce a new approached based on the possibility of compartmentalization of biomaterials and cells, controlling density over a gradient architecture to closely mimic osteochondral defects. By incorporating flow-focusing and passive mixer printhead modules, we achieved rapid and dynamic modulation of fiber diameter and material composition, driving compartmentalization of human bone marrow stromal cells (HBMSCs) into distinct three-dimensional layers with defined density patterns, demonstrating functional responses based on final concentration. Experiments conducted ex vivo and in vivo confirmed the functionality of 3D Bioprinted constructs containing patterned growth factors and cellular components. Consequently, this approach enables the simulation of diverse cellular environments and proliferation pathways within the same construct, a capability not achievable with conventional bioprinting techniques. These findings present new opportunities for fabricating functionally graded materials and physiologically relevant skeletal tissue substitutes, for the support in TERM applications for an ageing population.

This study investigates the dielectric relaxations of an unsaturated polyester matrix (PS) reinforced with varying weight fractions of argan nutshell powder (ANS) as a biofiller across temperatures ranging from 303 K to 453 K and frequencies from 0.1 Hz to 1 MHz. At low temperatures and high frequencies, dielectric relaxations are primarily attributed to the dipolar polarization of water associated with argan nutshell powder (ANS) charges. As temperatures increase and within the intermediate frequency range, dielectric relaxations are attributed to the α-relaxation process resulting from the rubbery glass transition of the polyester matrix (PS). Beyond the glass transition temperature and at low frequencies, dielectric relaxations are associated with the interfacial polarization effect, arising from the accumulation of charges at the interfaces between the filler and the matrix. Filler/matrix interactions are further examined in terms of the interfacial polarization effect, with consideration given to the increase in the weight fraction of the argan nutshell powder (ANS). Additionally, this study elucidates the impact of filler/matrix interactions on the dielectric properties of the composite system, offering valuable insights into the role of argan nutshell powder (ANS) as a biofiller in enhancing the performance and functionality of an unsaturated polyester matrix (PS) for potential applications in materials engineering.

As the main mineral component of bone tissue, hydroxyapatite (HAp) shows promising potential in bone tissue engineering due to its similarity to the natural component of bone tissue and its ability to stimulate tissue regeneration. Understanding the processes for obtaining hydroxyapatite and its properties is key to the further development of modern bone tissue engineering techniques to improve the effectiveness of regenerative therapies for trauma and osteoarticular diseases. The wet precipitation method is an effective technique for obtaining hydroxyapatite (HAp) in bone tissue engineering. The process is simple, scalable and allows precise control of parameters such as temperature and pH. The advantage of this method is that HAp with different morphologies and microstructures can be obtained by modifying the process conditions. In addition, it is an economically attractive technique due to the low cost of raw materials and the simplicity of the process. The conclusion is that the wet precipitation method is a promising option for producing HAp for bone tissue engineering applications. The presented work presents a method for the synthesis of hydroxyapatite and its detailed characterization. The chemical composition and morphological properties were determined using the following research techniques: Fourier transform infrared spectroscopy, particle size analysis, electron microscopy observations, and X-ray diffraction analysis. The results indicate great potential for the application of bioceramics in medical applications.

The novelty of the presented work is the combination of selected calcium phosphates with titanium alloy via sintering. As a result of this work, porous gradient structures were obtained, which were then evaluated for physicochemical properties using techniques such as X-ray diffraction, XRD.

The authors gratefully the acknowledge financial support from the project “New Generation of Bioactive Laser Textured Ti/Hap Implants”, under acronym “BiLaTex”, carried out within the M-ERA.NET 3 Call 2022 program in the National Centre for Research and Development (ERA.NET3/2022/48/BiLaTex/2023).

Introduction: Eating disorders (EDs) have evolved into severe, complex, and life-threatening conditions, impacting individuals of all ages and inflicting significant physical and psychological repercussions. These disorders, including binge eating, restrictive eating, compulsive eating, irregular eating patterns, anorexia, bulimia, and orthorexia nervosa, pose an increased risk of suicide attempts, mortality, and comorbid conditions. Despite advances in therapeutic interventions, limited treatment effectiveness and high rates of relapse persist.

Methods: The methodology for this study involves conducting a literature review on EDs and biomaterial-based nanoencapsulation (BBNE), identifying suitable drug therapies, evaluating BBNE methods, developing personalized treatment strategies, assessing their efficacy through clinical trials, performing statistical analysis, and discussing findings and future directions.

Results: BBNE offers precise drug delivery (DD), controlled release, and compatibility with combination therapies, promoting personalized and safe treatment strategies. This approach enhances drug bioavailability and stability, potentially improving therapeutic success while minimizing systemic adverse effects and increasing treatment adherence. Its personalized nature enables the tailoring of treatment regimens to address the unique biological and psychological factors of EDs.

Conclusions: However, challenges such as scalability, regulatory approval, and long-term safety need to be addressed to facilitate the widespread adoption of BBNE in clinical practice. In conclusion, the progress in BBNE offers transformative possibilities for treating EDs. Hence, this research endeavors to investigate innovative strategies utilizing DD biomaterials to meet the treatment requirements of EDs and enhance the therapeutic efficacy.

Introduction

The continued emergence and rapid spread of drug-resistant bacteria, coupled with the lack of novel antibiotics, imply the urgent need for new antimicrobial agents. Host defense peptides (HDPs) have been extensively studied as promising drugs against drug-resistant bacterial infections due to their broad-spectrum antimicrobial activity and insusceptibility to drug resistance. However, their application is limited by inherent shortcomings such as low stability upon proteolysis, cumbersome and time-consuming synthesis, and high cost. Therefore, the development of HDP mimetics that are resistant to proteolysis, easy to synthesize, and possess in vivo antimicrobial capability is of great significance.

Methods

The peptoid polymer was tested against drug-resistant Gram-positive bacteria, persister cells, and biofilms. In vitro and in vivo toxicity tests confirmed the high biocompatibility of the polymer. Confocal characterization, ROS test and DNA binding experiment were used to demonstrate the antimicrobial mechanism. Finally, mouse models were used to confirm the in vivo antibacterial efficacy of the peptoid polymer.

Results

In this study, we synthesized a library of antibacterial peptoid polymers with various C-terminal functional groups via one-pot ring-opening polymerization of N-substituted N-carboxyanhydrides (α-NNCAs). The optimal peptoid polymer showed potent activity against methicillin-resistant Staphylococcus aureus (MRSA) planktonic bacteria, persister cells, and biofilm. It’s noteworthy that bacteria are unable to acquire resistance against the peptoid polymer owing to the antibacterial mechanism including the generation of reactive oxygen species and DNA binding. The preferred molecule exhibited effective in vivo anti-infectious performance in the mouse wound model, the mouse keratitis model, and the mouse peritonitis model induced by MRSA. In addition, the polymer also displayed potent in vitro and in vivo antibacterial activity against various other drug-resistant Gram-positive bacteria.

Conclusion

This study demonstrates the potential of peptoid polymers mimicking HDP in the treatment of drug-resistant microbial infections, mitigation of antibiotic resistance and development of antibacterial materials.