3T3 Fibroblasts Research Articles

Development of a novel anti-tuberculosis nanodelivery formulation using magnesium layered hydroxide as the nanocarrier and pyrazinamide as a model drug

Designing and synthesizing biodegradable drug delivery systems are key research areas in biomedical nanotechnology. Here, we report the development of biodegradable magnesium-layered hydroxide (MgLH) based nanodelivery systems using magnesium oxide (MgO) as the precursor by a precipitation method. The designed nanocarrier does not contain any trivalent metal ions, which are most commonly used for the synthesis of layered double hydroxides (LDHs). The designed delivery system was characterized in detail using X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, Thermogravimetric analysis (TGA), Transmission electron microscopy (TEM) and inductively coupled plasma (ICP) analyses. The anti-tuberculosis (anti-TB) drug pyrazinamide (PZA) was successfully intercalated into interlayer galleries of MgLH, resulting in the formation of the nanocomposite, PZA-MgLH, having an average size of about 107 ± 24 nm with a uniform circular shape. The in vitro release of PZA in a human body simulated phosphate buffer saline (PBS) solution was sustained (i.e., almost 66 h) and followed a pseudo-secondorder kinetic model. Moreover, the designed nanodelivery system was found to be highly biocompatible with human normal lung cells (MRC-5) and with 3T3 fibroblast cells as controls for 24 and 48 h. Lastly, the PZA-MgLH nanocomposite showed good anti-tuberculosis activity against Mycobacterium tuberculosis and both the PZA-MgLH nanocomposite and its released free drug PZA showed antibacterial activity against tested Gram-positive and Gram-negative bacteria with percentage inhibition ranging from 5.6% to 68% against S. aureus, E. coli, and P. aeruginosa for the PZA free drug, and 32% to 32.5% against E. coli for the PZA-MgLH nanocomposite. In summary, the present results provide significant evidence that the designed nanodelivery system can be used for the delivery of PZA and, thus, should be investigated further for a wide range of anti-TB applications.

Mitigating the toxicity of palmitoylated analogue of α-melanocyte stimulating hormone(11-13) by conjugation with gold nanoparticle: characterisation and antibacterial efficacy against methicillin sensitive and resistant Staphylococccus aureus.

In an attempt to develop potent and non-toxic antimicrobial agent, the palmitoylated analogue of α-melanocyte stimulating hormone(11–13), Pal-α-MSH(11–13) was conjugated with gold nanoparticles (GNPs) for the first time and the efficacy of derived complex was investigated against two strains of Staphylococccus aureus. The GNPs were synthesized using tri-sodium citrate as reductant and Pal-α-MSH(11–13) was conjugated thereafter. The particles were characterised by UV-vis spectroscopy, transmission electron microscopy, dynamic light scattering, fourier transform infrared spectroscopy etc. Conjugation occurred via electrostatic interaction between anionic GNPs and cationic Pal-α-MSH(11–13). The zeta potential of GNP-Pal-α-MSH(11–13) was − 26.91, indicating its stability. The antibacterial activity was determined by minimal inhibitory concentration (MIC) and killing kinetics assay, whereas, inhibition of biofilm formation was studied by determining the biofilm biomass by crystal violet dye binding method, viability of biofilm-embedded cells by counting CFUs and metabolic activity by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. The toxicity was analysed by hemolysis assay against murine RBCs and cytotoxicity against 3T3 fibroblasts. The MIC was 18 µM for GNP-Pal-α-MSH(11–13) and 12 µM for Pal-α-MSH(11–13). The killing kinetics and biofilm inhibition studies indicated the comparable efficacy of peptide before and after nano-conjugation. Importantly, the conjugation resulted in diminished toxicity, as evidenced by 0.29 ± 0.03% hemolysis and 100% viable fibroblasts at 72 µM compared to the Pal-α-MSH(11–13), showing 74.99 ± 1.59% hemolysis and 59.39 ± 1.06% viable fibroblasts. The nano-fabrication drastically reduced the peptide toxicity without compromising its antibacterial efficacy. The anionicity of the conjugate may be responsible for non-toxicity that makes them suitable for pharmaceutical applications.Supplementary InformationThe online version contains supplementary material available at 10.1007/s11274-022-03365-7.

Antibacterial and Anticancer Activities of Pleurocidin-Amide, a Potent Marine Antimicrobial Peptide Derived from Winter Flounder, Pleuronectes americanus.

The extensive use of conventional antibiotics has led to the growing emergence of many resistant strains of pathogenic bacteria. Evidence suggests that cationic antimicrobial peptides (AMPs) have the greatest potential to serve as traditional antibiotic substitutes. Recent studies have also reported that certain AMPs have selective toxicity toward various types of cancer cells. The electrostatic attraction between the negatively charged membrane components and AMPs is believed to play a crucial role in the disruption of bacterial and cancer cell membranes. In the current study, we used a potent AMP called Pleurocidin (Ple) derived from winter flounder Pleuronectes americanus and its C-terminal-amidated derivative Pleurocidin-amide (Ple-a), and evaluated their antibacterial and anticancer activities. Our results indicated that both Ple and Ple-a exhibited significant antibacterial activity against a broad spectrum of Gram-positive and Gram-negative bacteria, especially marine pathogens, with MIC values ranging from 0.25 to 32 μg/mL. These peptides are also potent against several multidrug-resistant (MDR) bacterial strains, with MIC values ranging from 2 to 256 μg/mL. When used in combination with certain antibiotics, they exhibited a synergistic effect against MDR E. coli. Ple and Ple-a also showed notable cytotoxicity toward various cancer cell lines, with IC50 values ranging from 11 to 340 μM, while normal mouse fibroblast 3T3 cells were less susceptible to these peptides. Ple-a was then selected to study its anticancer mechanism toward A549 human lung adenocarcinoma cells. Western blot analysis and confocal microscopy showed that Ple-a could inhibit autophagy of A549 cells, and induce apoptosis 48 h after treatment. Our findings provided support for the future application of Ple-a as potential therapeutic agent for bacterial infections and cancer treatment.

Cardinal acuity on the extraction and characterization of soluble collagen from the underutilized abattoir junks for clinical demands

Improper utilization of solid wastes causes environmental flusters by prying the live organisms in the form of abattoir scraps. One of the most common underutilized biowastes in slaughter houses are bovine Achilles Tendons (AT). It has the rich source of type I collagen, since AT is composed of stiff and rigid materials, the collagen yield in the solubilized form is almost non pragmatic with conservative methods. Herein, this work emphasis the state-of-art on the design of seamless technique for the extraction of collagenous proteins with complete solubilization for clinical and healthcare application. High yield of soluble collagen (72%) was obtained through pepsin digestion coupled ultrasonic wave method. The triple helical structure of the native soluble type I collagen was confirmed through electrophoresis, circular dichroism (CD) and vibrational circular dichroism (VCD) analysis. The scanning electron microscopy (SEM) depicts the highly interconnected microfibrillar porous structure of the collagen as scaffold. The in vitro biocompatibility and fluorescent activity on NIH 3T3 fibroblast cells over the microfibrillar collagen scaffold possess excellent cell viability and proliferation at different time. Thus, it can be concluded that the AT-Collagen could be promising value-added bloom to bioeconomic growth for healthcare industries.

Quercetin functionalized hybrid electrospun nanofibers for wound dressing application

Quercetin is a potential phytochemical with high anti-inflammatory and antioxidant activities known to treat numerous ailments. In this study, quercetin loaded polycaprolactone (PCL)/gelatin (GLN) electrospun nanofiber was synthesized and their wound healing efficiency was evaluated. The results showed that the quercetin loaded nanofibers had a continuous, smooth and bead-free morphology with improved surface hydrophilicity. The quercetin incorporated nanofibers exhibited greater mechanical strength with bactericidal activity. The biocompatibility of the synthesized nanofibers on 3T3 fibroblast cells was examined by MTT assay and AO/EtBr staining. Further, the wound healing efficiency was evaluated in vivo on male Wistar rats. The in vivo study revealed a significant contraction of the wounds within 18 days with increased angiogenesis, reepithelization and collagen synthesis for quercetin nanofibers treated wounds. Overall, as synthesized nanofibers provided desired integrity and hydrophilicity to develop the therapeutic system for wound dressing applications.

Functional and biological heterogeneity of KRASQ61 mutations.

Missense mutations at the three hotspots in the guanosine triphosphatase (GTPase) RAS-Gly12, Gly13, and Gln61 (commonly known as G12, G13, and Q61, respectively)-occur differentially among the three RAS isoforms. Q61 mutations in KRAS are infrequent and differ markedly in occurrence. Q61H is the predominant mutant (at 57%), followed by Q61R/L/K (collectively 40%), and Q61P and Q61E are the rarest (2 and 1%, respectively). Probability analysis suggested that mutational susceptibility to different DNA base changes cannot account for this distribution. Therefore, we investigated whether these frequencies might be explained by differences in the biochemical, structural, and biological properties of KRASQ61 mutants. Expression of KRASQ61 mutants in NIH 3T3 fibroblasts and RIE-1 epithelial cells caused various alterations in morphology, growth transformation, effector signaling, and metabolism. The relatively rare KRASQ61E mutant stimulated actin stress fiber formation, a phenotype distinct from that of KRASQ61H/R/L/P, which disrupted actin cytoskeletal organization. The crystal structure of KRASQ61E was unexpectedly similar to that of wild-type KRAS, a potential basis for its weak oncogenicity. KRASQ61H/L/R-mutant pancreatic ductal adenocarcinoma (PDAC) cell lines exhibited KRAS-dependent growth and, as observed with KRASG12-mutant PDAC, were susceptible to concurrent inhibition of ERK-MAPK signaling and of autophagy. Our results uncover phenotypic heterogeneity among KRASQ61 mutants and support the potential utility of therapeutic strategies that target KRASQ61 mutant-specific signaling and cellular output.

Nanoinspired Biocompatible Chemosensors: Progress toward Efficient Prognosis of Arsenic Poisoning.

Diagnosing heavy metals poisoning in human beings is of paramount importance. In this work, we present the design of a biocompatible FexNi(1-x)O hierarchical nanostructure-based sensor for ultraselective detection of arsenate (As(V)) ions in biological environments (e.g., body fluids, blood plasma, etc.). A novel iron doping technique was employed to fabricate the nanostructures rich with Fe cores to induce ultraselectivity toward arsenates. These nanostructures were used as dispersed markers and thin films deposited on Si/SiO2 substrates to support in vivo and in vitro detection of As(V) ions. The device demonstrated excellent sensitivity with a maximum response of 64.7% (for 1000 ppm As(V) ions) with a limit of detection of 1 ppb in blood plasma. The sensor's response time (τr) was 5 s with 95.48% recovery with a maximum error of ±0.549% after three washes. The device showed excellent response stability for 63 days with a maximum error of ±1.27%. The sensor devices were highly reproducible, with a maximum variation of ±0.6% in response for a batch of four devices. Due to Fe doping, the nanostructures in suspension demonstrated as arsenate markers with excellent cytocompatibility (with dosage up to 1 mg/mL) for human umbilical vein endothelial cells and 3T3 fibroblasts (LDH < 120 and cell viability ∼80%) till 48 h of incubation. The sensing mechanism suggested that the nanostructures not only detect arsenates but also prevent their substantial reduction to arsenites under anoxic environments. Thus, the sensors may show considerable progress toward early arsenate detection in living systems.

Three-dimensional tailor-made collagen-like proteins hydrogel for tissue engineering applications.

Despite the potential tunable properties of blank slate collagen-like proteins (CLP), an alternative to animal-originated collagen, assembling them into a stable 3D hydrogel to mimic extracellular matrix is a challenge. To address this constraint, the CLP (without hydroxyproline, CLPpro) and its variants encoding functional unnatural amino acids such as hydroxyproline (CLPhyp) and 3,4-dihydroxyphenylalanine (CLPdopa) were generated through genetic code engineering for 3D hydrogel development. The CLPhyp and CLPdopa were chosen to enhance the intermolecular hydrogen bond interaction through additional hydroxyl moiety and thereby facilitate the self-assembly into a fibrillar network of the hydrogel. Hydrogelation was induced through genipin as a cross-linker, enabling intermolecular cross-linking to form a hydrogel. Spectroscopic and rheological analyses confirmed that CLPpro and its variants maintained native triple-helical structure, which is necessary for its function, and viscoelastic nature of the hydrogels, respectively. Unlike CLPpro, the varients (CLPhyp and CLPdopa) increased pore size formation in the hydrogel scaffold, facilitating 3T3 fibroblast cell interactions. DSC analysis indicated that the stability of the hydrogels got increased upon the genetic incorporation of hydroxyproline (CLPhyp) and dopa (CLPdopa) in CLPpro. In addition, CLPdopa hydrogel was found to be relatively stable against collagenase enzyme compared to CLPpro and CLPhyp. It is the first report on 3D biocompatible hydrogel preparation by tailoring CLP sequence with non-natural amino acids. These next-generation tunable CLP hydrogels open a new venue to design synthetic protein-based biocompatible 3D biomaterials for tissue engineering applications.

Lamellipodia-like actin networks in cells lacking WAVE regulatory complex.

ABSTRACTCell migration frequently involves the formation of lamellipodia induced by Rac GTPases activating WAVE regulatory complex (WRC) to drive Arp2/3 complex-dependent actin assembly. Previous genome editing studies in B16-F1 melanoma cells solidified the view of an essential, linear pathway employing the aforementioned components. Here, disruption of the WRC subunit Nap1 (encoded by Nckap1) and its paralog Hem1 (encoded by Nckap1l) followed by serum and growth factor stimulation, or active GTPase expression, revealed a pathway to formation of Arp2/3 complex-dependent lamellipodia-like structures (LLS) that requires both Rac and Cdc42 GTPases, but not WRC. These phenotypes were independent of the WRC subunit eliminated and coincided with the lack of recruitment of Ena/VASP family actin polymerases. Moreover, aside from Ena/VASP proteins, LLS contained all lamellipodial regulators tested, including cortactin (also known as CTTN), the Ena/VASP ligand lamellipodin (also known as RAPH1) and FMNL subfamily formins. Rac-dependent but WRC-independent actin remodeling could also be triggered in NIH 3T3 fibroblasts by growth factor (HGF) treatment or by gram-positive Listeria monocytogenes usurping HGF receptor signaling for host cell invasion. Taken together, our studies thus establish the existence of a signaling axis to Arp2/3 complex-dependent actin remodeling at the cell periphery that operates without WRC and Ena/VASP.

Effect of Peroxiredoxin 6 on p53 Transcription Factor Level.

Peroxiredoxin 6 (Prdx6) is an important antioxidant enzyme with multiple functions in the cell. Prdx6 neutralizes a wide range of hydroperoxides, participates in phospholipid metabolism and cell membrane repair, and in transmission of intracellular and intercellular signals. Disruption of normal Prdx6 expression in the cell leads to the development of pathological conditions. Decrease in the Prdx6 concentration leads to increase in oxidative damage to the cell. At the same time, hyperproduction of Prdx6 is associated with increase in antioxidant status, suppression of apoptosis, and carcinogenesis. Currently, mechanisms of carcinogenic action of peroxiredoxins are poorly understood. In this work we established that the 3-4-fold increase in Prdx6 production in mouse embryonic fibroblast 3T3 cells leads to the 4-5-fold decrease in the level of oncosuppressor p53. At the same time, hyperproduction of Prdx6 leads to the increased expression of RELA and HIF1A, which have oncogenic effects. The 3-4-fold increase in intracellular Prdx6 increases intensity of cell proliferation by 20-30%, promotes increase in antioxidant activity by 30-50%, and increases radioresistance of the transfected 3T3 cells by 30-40%. Increase of the level of intranuclear Prdx6 leads to the decrease in expression of the DNA repair genes in response to radiation, indicating decrease in the genomic DNA damage. This work discusses possible molecular mechanisms of p53 suppression during Prdx6 hyperproduction, which could be used in the development of new approaches in cancer therapy.

Evaluation of nanofibril chitosan@8‐formyl‐7‐hydroxy‐coumarin hydrogel having distinct auto‐fluorescence efficiency: Structure–properties relation, improved antioxidant, and cellular imaging

AbstractThe modification at the branching of chitosan using 8‐formyl‐7‐hydroxy‐coumarin (ChCm) through chemically cross‐linked has been structured for hydrogel fabrication. ChCm produced stable mechanical properties, improved swelling capacity, and delayed degradation for new cross linking‐functionalized during experimental works. It also imparted high antioxidant potency. The swelling water ratio of this hydrogel makes it robust and elastic, providing a mechanical basis to keep the hydrogel strong and steady. A remarkable self‐fluorescence behavior has been witnessed. The distinct photo‐sensitiveness has been studied thoroughly as time, temperature, and solvent‐dependent spectral analysis to establish the ESIPT mechanism and improve stability in various conditions. Detailed instrumental‐structural evaluations are explored as required, and optimized the gel skeleton and photo activities are using DFT calculations. The effectiveness of radical scavenging using DPPH, antioxidant power using FRAP assay, and chelation ability have been observed during the evaluation of antioxidant potency for hydrogel. The role of phenolic‐OH is very significant not only for optical fluorescence enhancement by ESIPT but also for the improved antioxidant abilities. As well as being less toxic, bio‐compatible, and photostable, it could be used to image fibroblast 3T3 cells by fluorescence; current hydrogel has gained vast potential for developing dynamic biomaterials in multiple applications.

Fabrication and Evaluation of Electrospun Silk Fibroin/Halloysite Nanotube Biomaterials for Soft Tissue Regeneration.

The production of nanofibrous materials for soft tissue repair that resemble extracellular matrices (ECMs) is challenging. Electrospinning uniquely produces scaffolds resembling the ultrastructure of natural ECMs. Herein, electrospinning was used to fabricate Bombyx mori silk fibroin (SF) and SF/halloysite nanotube (HNT) composite scaffolds. Different HNT loadings were examined, but 1 wt% HNTs enhanced scaffold hydrophilicity and water uptake capacity without loss of mechanical strength. The inclusion of 1 wt% HNTs in SF scaffolds also increased the scaffold’s thermal stability without altering the molecular structure of the SF, as revealed by thermogravimetric analyses and Fourier transform infrared spectroscopy (FTIR), respectively. SF/HNT 1 wt% composite scaffolds better supported the viability and spreading of 3T3 fibroblasts and the differentiation of C2C12 myoblasts into aligned myotubes. These scaffolds coated with decellularised ECM from 3T3 cells or primary human dermal fibroblasts (HDFs) supported the growth of primary human keratinocytes. However, SF/HNT 1 wt% composite scaffolds with HDF-derived ECM provided the best microenvironment, as on these, keratinocytes formed intact monolayers with an undifferentiated, basal cell phenotype. Our data indicate the merits of SF/HNT 1 wt% composite scaffolds for applications in soft tissue repair and the expansion of primary human keratinocytes for skin regeneration.

A composite scaffold fabricated with an acellular matrix and biodegradable polyurethane for the in vivo regeneration of pig bile duct defects

Bile duct regeneration is urgently needed to restore the normal function of the damaged biliary system. In this study, an artificial bile duct (ABD) was fabricated for extrahepatic bile duct regeneration based on biodegradable polyurethane (BPU) and ureter acellular matrix (UAM) to endow it with favorable biocompatibility and eliminate bile leakage during in vivo bile duct regeneration. The mechanical properties, in vitro simulation of bile flow and cytocompatibility of BPU-UAM ABD were evaluated in vitro, and surgical implantation in the biliary defect site in minipigs was implemented to reveal the in vivo degradation of BPU-UAM and regeneration of the new bile duct. The results indicated that BPU-UAM ABD with a mechanical strength of 11.9 MPa has excellent cytocompatibility to support 3T3 fibroblast survival and proliferation in extraction medium and on the scaffolds. The in vivo implantation of BPU-UAM ABD revealed the change of collagen content throughout the new bile duct regeneration. Biliary epithelial cells were observed at day 70, and continuous biliary epithelial layer formation was observed after 100 days of implantation. Altogether, the BPU-UAM ABD fabricated in this study possesses excellent properties for application study in the regeneration of bile duct. Statement of significanceExtrahepatic bile duct defects carry considerable morbidity and mortality because they are the only pathway for bile to go down into the intestinal tract. At present, no artificial bile duct can promote biliary regeneration. In this study, BPU-UAM ABD was built based on biodegradable polyurethane and ureter acellular matrix to form a continuous compact layer of polyurethane in the internal wall of UAM and avoid bile leakage and experimental failure during in vivo implantation. Our work verified the effectiveness of the synthesized biodegradable polyurethane emulsion-modified urethral acellular matrix in bile regeneration and continuous biliary epithelial layer formation. This study provided a new approach for the curing of bile duct defects and inducing new bile tissue formation.

Antimicrobial and anticancer potential of novel polyaspartate derivatives synthesized via quaternary ammonium grafting

AbstractThree novel polyaspartate derivatives with antibacterial properties and low hemolytic effects are synthesized by the reaction of sodium polyaspartate (PAspNa) with different quaternary ammonium salts with a carboxylic end‐group, subsequently these are tested in vitro against different cancer and normal cell lines. 1‐(carboxypentyl) pyridinium bromide, 1‐(carboxypentyl) benzalkonium bromide, and 1‐(carboxypentyl) quinolinium bromide are synthesized from a quaternization reaction between 6‐bromohexanoic acid and the respective tertiary amines (pyridine, N,N‐dimethylbenzylamine, and quinoline). Then, these ammonium salts are chemically grafted along the sodium polyaspartate macromolecular chains through an acid–base reaction. Three different polyaspartate derivatives are obtained and their chemical structures analyzed and confirmed by FT‐IR and 1H NMR, the corresponding thermal stability is analyzed by thermogravimetric analysis. The antibacterial efficiency of these PAspNa derivatives against Escherichia coli is determined by measuring the minimum inhibitory concentration and the minimum bactericidal concentration. Hemolysis assays are performed on isolated human erythrocytes and finally the cell proliferation is studied by 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide (MTT) analysis. All the PAspNa derivatives show antibacterial activities, low hemolytic effects, and antiproliferative effect in some concentrations evaluated in murine fibroblast (3T3), and cancer cell lines of cervix (HeLa), breast (4T1), and liver (HepG2) cells lines.

Regenerative repair of full thickness skin wound assisted by dual crosslinking percolative gel casting maneuvered alginate hydrogel embedded with honey ghee blend resembles standard cutaneous properties

We report synergism in scarless cutaneous wound repair by alginate hydrogel (HGSAG) embedded with an optimized blend of characterized Jamun honey and characterized indigenously prepared ghee. Thorough screening and characterization of honey and ghee are carried out followed by obtaining a novel dual crosslinking percolative gel casting fabrication method to come up with HGSAG showing superior chemical stability, and mechanical strength (Nanoindentation study; lowest stiffness: 0.71 ± 0.19 μN/nm), and surface morphology (SEM; highest roughness: 0.13 ± 0.04 μm) to other variants. In vitro swelling study and degradation behavior study show intermediate swelling (swelling index: 0.59 ± 0.008 in 98 h) and required restricted degradation (PBS: 73.38 ± 0.55%, DMEM: 83.48 ± 0.69% in 10 days) for HGSAG which is necessary for providing nutrients to cells and in vivo therapeutic efficacy. We observe the remarkable antibacterial efficacy of HGSAG against Staphylococcus mutans and Escherichia coli. This particular substrate also shows decent 3T3 fibroblasts viability, cell-cell communication followed by cell-matrix interaction, and proliferation compared to other variants. Molecular gene expression studies by quantitative RT-PCR technique reveal strong upregulation of collagen I, CD26, and TGF-β3 while downregulation in the case of TGF-β1 which eventually substantiates scarless wound healing potential of HGSAG. Wound closure kinetics is most rapidly and successfully underpinned by HGSAG while compared to other alternatives including marketed healing patches. Regular close monitoring using histopathological studies and real-time imaging by Swept-Source Optical Coherence Tomography of in vivo wound model treated with HGSAG come up with the fascinating result of scarless healing (HGSAG treated epithelial thickness: 62.96 ± 0.67 μm, unwounded akin epithelial thickness: 62.56 ± 0.34 μm) within 12 days of wounding. Thus, the work highlights modified and stabilized alginate hydrogel embedded with honey and ghee blend as a potential scarless full-thickness cutaneous wound healing bio-scaffold.

NANOCERIA INFUSED CHITOSAN-PVA HYDROGELS TO TREAT BURN WOUNDS

Burn wounds are highly dangerous injuries with significant mortality rates. They are painful and increase the risk of bacterial infection. Burn wounds could also harm adjacent tissues by releasing dangerous compounds. Thus, their treatment should work quickly and effectively. Hydrogels are used as burn wound dressings that provide a suitable environment for regeneration. They closely imitate the structure of the skin’s extracellular matrix and have high water uptake properties, providing a moist environment for faster healing. Chitosan-PVA based hydrogels demonstrated antibacterial and healing effects on wounds. Nanoparticles of cerium oxide called nanoceria were shown to reduce local oxidative stress by decomposing reactive oxygen species. The goal of this study is to learn the effects of nanoceria infused chitosan-PVA hydrogels on wound regeneration. We characterized hydrogels with various chitosan-PVA ratios, crosslinked with tetraethyl orthosilicate. These trials improved the procedure for making hydrogels capable of maintaining a moist environment for better wound healing. Further experiments demonstrated the biocompatibility and antibacterial properties of the hydrogels crosslinked with glutaraldehyde, where 3T3 fibroblasts seeded on the hydrogels were shown to be viable and zone of inhibition tests performed with E. coli demonstrated the antibacterial capacity of the hydrogels. Future studies will determine the antioxidant capacity and further bioactive properties of the nanoceria infused hydrogel. Once the small-scale procedure is well established the proposed methods could be implemented in clinical applications to aid in burn wound recovery.

Characterization of Gels and Films Produced from Pinhão Seed Coat Nanocellulose as a Potential Use for Wound Healing Dressings and Screening of Its Compounds towards Antitumour Effects.

The reuse of agro-industrial waste assumes great importance today. Pinhão is the seed of Araucaria angustifolia, which is native to the mountains of southern Brazil, Paraguay, and Argentina. The coat is a by-product of this seed and is rich in phenolic compounds. The present study aimed to use the residue as a precursor material for the production of nanocellulose through the mechanical defibrillation process and perform the characterization of the films and the gel to investigate the effect on the physical and regenerative properties when incorporated with polyvinyl alcohol (PVA). The modulus of elasticity was higher when the MFC of pinhão was added to the PVA. Film and gel had their cytotoxicity tested by MTT assay using 3T3 fibroblast and Schwann cancer cells, and a migration assay was also performed using the scratch test on HaCat keratinocyte cells. For the scratch test, film and gel samples with low concentration presented a complete scratch closure in 72 h. Molecular docking was performed and quercetin had the ideal interaction score values, so it was used with the PACAP protein which presented a slightly moderate interaction with the protein synthesis of Schwann cells, presenting compactness of the compound after 14 ns.

CYTOTOXICITY AND WOUND HEALING CAPACITY OF BIOLOGICALLY SYNTHESIZED SILVER NANOPARTICLES

Metallic nanoparticles are interesting areas of research due to their unique properties which can be advantageous for producing smart products. Silver nanoparticles (AgNPs) are remarkably used in pharmaceutical industry because of their strong biological activities. The aim of the present study was to investigate the cytotoxicity and wound healing capacity of the biologically prepared silver nanoparticles via green synthesis route. Cytotoxicity of the biogenic AgNPs was determined by MTT (3- [4, 5- dimethyl-2-thiazolyl]-2, 5-diphenyl-2H-tetrazolium-bromide) assay against L929 fibroblast cell line. Wound healing properties of the AgNPs were evaluated using in vitro-scratch wound healing assay using 3T3 fibroblast cell line. Biosynthesized AgNPs inhibited the propagation of fibroblasts at a half maximal inhibitory concentration (IC50) of 23.507 μg/mL after 24 h incubation. In vitro wound healing assay also revealed that the biogenic AgNPs stimulated the 3T3 fibroblasts' cell proliferation. It can be suggested that biologically synthesized AgNPs can be used effectively for biomedical applications such as wound dressing materials.

Strontium Substituted Tricalcium Phosphate Bone Cement: Short and Long‐Term Time‐Resolved Studies and In Vitro Properties

AbstractDue to a significant influence of strontium (Sr) on bone regeneration, Sr substituted β‐tricalcium phosphate (Sr‐TCP) cement is prepared and investigated by short‐ and long‐term time‐resolved techniques. For short‐term investigations, energy‐dispersive X‐ray diffraction, infrared spectroscopy, and, for the first time, terahertz time‐domain spectroscopy techniques are applied. For long‐term time‐resolved studies, angular dispersive X‐ray diffraction, scanning electron microscopy, mechanical tests, and behavior in Ringer solution are carried out. After 45 min of the cement setting, the Sr‐TCP phase is no longer detectable. During this time period, an appearance and constant increase of the final brushite phase are registered. The compressive strength of the Sr‐TCP cement increases from 4.5 MPa after 2 h of setting and reaches maximum at 13.3 MPa after 21 d. After cement soaking for 21 d in Ringer solution, apatite final product, with an admixture of brushite and TCP phases is detected. The cytotoxicity aspects of the prepared cement are investigated using NCTC 3T3 fibroblast cell line, and the cytocompatibility—by human dental pulp mesenchymal stem cells. The obtained results allow to conclude that the developed Sr‐TCP cement is promising for biomedical applications for bone tissue.

Fabrication of Gelatin Nanofibers by Electrospinning-Mixture of Gelatin and Polyvinyl Alcohol.

Gelatin, one of the most abundant, naturally derived biomacromolecules from collagen, is widely applicable in food additives, cosmetic ingredients, drug formulation, and wound dressing based on their non-toxicity and biodegradability. In parallel, polyvinyl alcohol (PVA), a synthetic polymer, has been commonly applied as a thickening agent for coating processes in aqueous systems and a major component in healthcare products for cartilage replacements, eye lubrication, and contact lenses. In this study, a new type of mixed hydrogel nanofiber was fabricated from gelatin and polyvinyl alcohol by electrospinning under a feasible range of polymer compositions. To determine the optimal composition of gelatin and polyvinyl alcohol in nanofiber fabrication, several key physicochemical properties of mixed polymer solutions such as viscosity, surface tension, pH, and electrical conductance were thoroughly characterized by a viscometer, surface tensiometer, water analyzer, and carbon electron probe. Moreover, the molecular structures of polymeric chains within mixed hydrogel nanofibers were investigated with Fourier-transform infrared spectroscopy. The morphologies and surface elemental compositions of the mixed hydrogel nanofibers were examined by the scanning electron microscope and energy-dispersive X-ray spectroscopy, respectively. The measurement of water contact angles was performed for measuring the hydrophilicity of nanofiber surfaces. Most importantly, the potential cytotoxicity of the electrospun nanofibers was evaluated by the in vitro culture of 3T3 fibroblasts. Through our extensive study, it was found that a PVA-rich solution (a volumetric ratio of gelatin/polyvinyl alcohol <1) would be superior for the efficient production of mixed hydrogel nanofibers by electrospinning techniques. This result is due to the appropriate balance between the higher viscosity (~420–~4300 10−2 poise) and slightly lower surface tension (~35.12–~32.68 mN/m2) of the mixed polymer solution. The regression on the viscosity data also found a good fit by the Lederer–Rougier’s model for a binary mixture. For the hydrophilicity of nanofibers, the numerical analysis estimates that the value of interfacial energy for the water contact on nanofibers is around ~−0.028 to ~−0.059 J/m2.