Biocompatibility Assays Research Articles

Fabrication and biocompatibility analysis of flexible organic light emitting diodes on poly(lactic acid) substrates: toward the development of greener bio‐electronic devices

AbstractThe use of biodegradable and biocompatible materials for electronic applications is a research topic of great interest, offering the possibility to develop bio‐electronic devices and reduce e‐wastes. In this work, poly(lactic acid) (PLA) films were prepared to be employed as substrates in flexible optoelectronic devices and their functionality was tested in indium tin oxide‐free organic light emitting diodes (OLEDs). The PLA substrates were fabricated by extrusion and characterized in terms of morphological, optical and wettability properties. The films showed optical transmittance of about 90% in the visible region and surface roughness of about 12 nm, optical and morphological parameters suitable for OLED applications. Different structures were fabricated on top of the PLA substrates by hybrid technology through solution‐based and thermal evaporation deposition methods. Good electro‐optical properties were detected in iridium complexes‐based devices, with current efficiencies of about 14 and 1 cd/A in structures with tris[2‐phenylpyridinato‐C2,N]iridium(III) (Ir[ppy]3) and bis[2‐(4,6‐difluorophenyl)pyridinato‐C2,N](picolinato)iridium (FIrPic) as emitting layer, respectively. The biocompatibility assay showed that the encapsulated devices do not release toxic substances and their biocompatibility can be improved by selecting different encapsulating glues. The results of this study show the potentiality of PLA as substrate for the fabrication of biocompatible and biodegradable optoelectronic devices opening new routes for the development of advanced bio‐electronic systems.

Polydopamine surface functionalization of 3D printed resin material for enhanced polystyrene adhesion towards insulation layers for 3D microelectrode arrays (3D MEAs).

3D printing involves the use of photopolymerizable resins, which are toxic and typically have incompatible properties with materials such as polystyrene (PS), which present limitations for biomedical applications. We present a method to dramatically improve the poor adhesion between the PS insulative layer on 3D printed Microelectrode Array (MEA) substrates by functionalizing the resin surface with polydopamine (PDA), a mussel-inspired surface chemistry derivative. A commercial 3D printing prepolymer resin, FormLabs Clear (FLC), was printed using a digital light processing (DLP) printer and then surface functionalized with PDA by alkali-induced aqueous immersion deposition and self-polymerization. It was observed that the adhesion of the PS to FLC was improved due to the precision emanating from the DLP method and further improved after the functionalization of DLP printed substrates with PDA at 1, 12, and 24 h time intervals. The adhesion of PS was evaluated through scotch tape peel testing and instron measurements of planar substrates and incubation testing with qualitative analysis of printed culture wells. The composition and topology of the samples were studied to understand how the properties of the surface change after PDA functionalization and how this contributes to the overall improvement in PS adhesion. Furthermore, the surface energies at each PDA deposition time were calculated from contact angle studies as it related to adhesion. Finally, biocompatibility assays of the newly modified surfaces were performed using mouse cardiac cells (HL-1) to demonstrate the biocompatibility of the PDA functionalization process. PDA surface functionalization of 3D DLP printed FLC resin resulted in a dramatic improvement of thin film PS adhesion and proved to be a biocompatible solution for improving additive manufacturing processes to realize biosensors such as in vitro MEAs.

Effect of Hafnium Coating on Osseointegration of Titanium Implants: A Split Mouth Animal Study

The behaviour of hafnium as surface coating in biological environments has not been studied. Little is known about osseointegration of hafnium-coated titanium implants. Thus, further studies of hafnium coating under biological conditions are required in order to determine the suitability of this material, as a surface coating for biomedical application. The aim of the study is to analyse the difference between hafnium-coated titanium and uncoated titanium by evaluating the osseointegration ability of hafnium metal and mechanism of which promotes better bone integration. The study was conducted with a split mouth design on 16 Wistar Albino rats of both sexes, at the age of 6-7 months, weighing 2526.5 ± 74.4 g . Self-tapping titanium osteosynthesis screws ( 4 mm × 2 mm ) (LeForte System Bone Screw®) were implanted in the mandible of rats: Group A (pure titanium screws, n = 12 ) and Group B (hafnium-coated screws, n = 12 ). The implanted screws’ stability was checked and noted with a specially customised torque apparatus during insertion and removal of implant. The tissue sections were then processed for hematoxylin and eosin and Masson’s trichrome for bone and connective tissue examination, after 4 and 8 weeks of placement. Hafnium coating appears to have offered similar biocompatibility (aspartate transaminase (AST), alanine aminotransferase (ALT), and creatine kinase (CK) enzyme assay), statistically significant improvement (independent Student’s t -test, p < 0.05 ) in insertion torque ( 25.42 ± 3.965 ) and removal torque ( 29.17 ± 2.887 ) than commercially pure titanium with insertion torque ( 22.08 ± .575 ) and removal torque ( 25.42 ± 2.575 ). Hafnium coating in the rat mandible showed promising osseointegration with good tissue biocompatibility. Further human trials of hafnium-coated implants are needed to understand the biological behaviour better to enhance clinical performance.

Acellular Porcine Cornea Produced by Supercritical Carbon Dioxide Extraction: A Potential Substitute for Human Corneal Regeneration.

The aim of this study was to develop a non-cytotoxic, biocompatible innovative acellular porcine cornea (APC) for corneal wound healing and corneal blindness treatment. APC was produced by using supercritical carbon dioxide (SCCO2) to decellularize the porcine cornea. Decellularization of the porcine cornea was examined by hematoxylin and eosin staining and 4,6-diamidino-2-phenylindole, dihydrochloride staining. The residual DNA content of APC was analyzed in comparison with the native porcine cornea. Virus inactivation up to at least 6 log10 was confirmed for the stepwise process of APC for 4 different model viruses. In addition, a series of in vitro and in vivo tests in accordance with ISO-10993 biocompatibility assay and animal performance tests were performed. APC produced by the SCCO2 process revealed complete decellularization, without any residual non-collagenous proteins. The scanning electron microscopy structural features of the decellularized cornea were similar to those of human. APC was found to be nontoxic and exhibited excellent biocompatibility in both in vitro and in vivo studies. The animal performance test proved that APC exerted excellent adaptability on the cornea and no sign of irritation and good compatibility in lamellar corneal transplantation. APC manufactured by SCCO2 technology revealed complete cells and non-collagenous protein removal compared with the Triton-sodium dodecyl sulfate decellularization process. APC showed excellent biocompatibility in rabbit lamellar corneal transplantation with a follow-up to 1 year. APC can be a potential substitute for human-donated cornea for corneal transplantation in the near future.

Thermo resistant antioxidants from photoautotrophic microorganisms: screening and characterization.

The demand for natural antioxidants to be used in food industry is increasing, as synthetic antioxidants are toxic and have high production costs. Specifically, food processing and preservation require antioxidants resistant to thermal sterilization processes. In this study, twenty-five strains among microalgae and cyanobacteria were screened as antioxidants producers. The species Enallax sp., Synechococcus bigranulatus and Galdieria sulphuraria showed the highest content of chlorophyll a and total carotenoids. In vitro stability and antioxidant activity of the ethanolic extracts were performed. The results revealed that pigments present in the extracts, obtained from the previously mentioned species, were stable at room temperature and exhibited in vitro free radical scavenging potential with IC50 values of 0.099 ± 0.001, 0.048 ± 0.001 and 0.13 ± 0.02mg mL-1, respectively. Biocompatibility assay showed that the extracts were not toxic on immortalized cell lines. The antioxidant activity was also tested on a cell-based model by measuring intracellular ROS levels after sodium arsenite treatment. Noteworthy, extracts were able to exert the same protective effect, before and after the pasteurization process. Results clearly indicate the feasibility of obtaining biologically active and thermostable antioxidants from microalgae. Green solvents can be used to obtain thermo-resistant antioxidants from cyanobacteria and microalgae which can be used in the food industry. Thus, the substitution of synthetic pigments with natural ones is now practicable.

Effect of targeting ligand designation of self-assembly chitosan-poloxamer nanogels loaded Paclitacel on inhibiting MCF-7 cancer cell growth

In this study, we investigated two formulations of chitosan-Pluronic P123 with different folate ligand designation for targeted delivery of Paclitaxel (PTX), in which folic acid (FA) was directly conjugated to chitosan (FA-Cs-P123) or substituted onto P123 (Cs-P123-FA). The results showed that the FA content of Cs-P123-FA was determined at 0.71 wt/wt% which was significantly higher than that of FA-Cs-P123 (0.31 wt/wt%). Two copolymers were low critical gel concentrations (CGC). FA-Cs-P123 and Cs-P123-FA nanogels performed high PTX encapsulation efficiency reaching 95.57 ± 5.51 and 92.51 ± 6.68 wt/wt%, respectively. Transmission electron microscopy (TEM) and zeta potential analysis indicated that the PTX-loaded nanogels were spherically formed around 60 nm in diameter along with positive charge. Furthermore, the PTX release profile was slow and it was controlled by the pH of the medium. In particular, in vitro biocompatibility assays indicated that both FA-Cs-P123 and Cs-P123-FA exhibited good biological compatibility with a human foreskin fibroblast cell line and well uptake efficiency into MCF-7 cancer cells. Cs-P123-FA nanogel significantly enhanced the cytotoxicity of PTX in comparison with FA-Cs-P123. The result indicates that Cs-P123-FA nanogels with a higher decorated FA content perform a better targeting efficiency; therefore, they could have great potential application towards breast cancer treatment.

Development of “on-demand” thermo-responsive hydrogels for anti-cancer drugs sustained release: Rational design, in silico prediction and in vitro validation in colon cancer models

A rational design accurate based on the use of Statistical Design of the Experiments (DoE) and Molecular Dynamics Simulations Studies allows the prediction and the understanding of thermo-responsive hydrogels prepared regarding their gelation temperature and anti-cancer drug release rate. N-isopropylacrilamide (NIPAM) modified with specific co-monomers and crosslinkers, can be used to prepare “on-demand” thermo-responsive hydrogels with the ideal properties for clinical applications in which local sustained release of drugs is crucial. Two preferential formulations resulting from the predictive studies of DoE and In Silico methods were synthesized by radical polymerization, fully characterized, and loaded with the anticancer drug Doxorubicin (Dox). The hydrogel formulations were characterized by swelling rate, turbidity, FTIR, 1H NMR, SEM, gelation time, rheology, and biocompatibility assays. Both formulations demonstrated adequate morphologic, rheological, and biocompatibility properties; however, important differences in terms of drug retention were detected. As demonstrated by a Dox cumulative release study and posteriorly confirmed by an efficacy assay in an in vitro colorectal cancer model, the formulation composed by NIPAM and 4-penten-1-ol crosslinked with poly(ethylene glycol) diacrylate (PEGDA) (PNiPenPH) present a slow release over the time, presenting ideal properties to become and ideal depot system for the local sustained release of anticancer drugs as adjuvant therapy or in the case of non-resectable tumors.

Resveratrol-Loaded Levan Nanoparticles Produced by Electrohydrodynamic Atomization Technique.

Considering the significant advances in nanostructured systems in various biomedical applications and the escalating need for levan-based nanoparticles as delivery systems, this study aimed to fabricate levan nanoparticles by the electrohydrodynamic atomization (EHDA) technique. The hydrolyzed derivative of levan polysaccharide from Halomonas smyrnensis halophilic bacteria, hydrolyzed Halomonas levan (hHL), was used. Nanoparticles were obtained by optimizing the EHDA parameters and then they were characterized in terms of morphology, molecular interactions, drug release and cell culture studies. The optimized hHL and resveratrol (RS)-loaded hHL nanoparticles were monodisperse and had smooth surfaces. The particle diameter size of hHL nanoparticles was 82.06 ± 15.33 nm. Additionally, release of RS from the fabricated hHL nanoparticles at different pH conditions were found to follow the first-order release model and hHL with higher RS loading showed a more gradual release. In vitro biocompatibility assay with human dermal fibroblast cell lines was performed and cell behavior on coated surfaces was observed. Nanoparticles were found to be safe for healthy cells. Consequently, the fabricated hHL-based nanoparticle system may have potential use in drug delivery systems for wound healing and tissue engineering applications and surfaces could be coated with these electrosprayed particles to improve cellular interaction.

An in vitro investigation into targeted paclitaxel delivery nanomaterials based on chitosan-Pluronic P123-biotin copolymer for inhibiting human breast cancer cells

Targeted chemotherapy is a current research trend in cancer treatment that aims to improve the effectiveness of drug access to cancer cells. Among the vitamins, biotin has been identified as an effective targeting agent in drug delivery to cancer cells. In this work, novel biotin-conjugated chitosan-Pluronic P123, termed Cs–P123-Bio, was developed as a carrier vehicle for delivering paclitaxel (PTX) to the tumour target. The results show that Cs–P123-Bio was stable with a low critical micelle concentration (31.83 ± 4.25 μg/mL), and the encapsulation efficacy and drug loading of Cs–P123-Bio were around 94.67 ± 3.67% and 1.89 ± 0.07%, respectively. Transmission electron microscopy (TEM), dynamic light scattering (DLS) and electrophoretic light scattering (ELS) analysis indicated that the Cs–P123-Bio nanoparticles loaded with PTX formed as a spherical shape with an average diameter of 63.4 ± 0.6 nm and a positive charge. Furthermore, the PTX release profile was slow and controlled by the pH of the medium. In particular, in vitro biocompatibility assays indicated that Cs–P123-Bio exhibited good biological compatibility with a human foreskin fibroblast cell line and Cs–P123-Bio manifested good internalization efficiency in MCF-7 cells. Cs–P123-Bio also enhanced the cytotoxicity of PTX in comparison with Cs–P123. Therefore, our approach could suggest excellent potential for tumour targeting in cancer therapy.

Biogenic synthesis, in-vitro cytotoxicity, esterase activity and interaction studies of copper oxide nanoparticles with lysozyme

Herein, we have shown the eco-friendly and low-cost synthesis of biogenic copper oxide nanoparticles (CuONPs) from Delonix regia (D. regia) leaf extract in aqueous medium. The formation of biogenic CuONPs was characterized by ultraviolet (UV)-visible, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and scanning electron microscopy (SEM) as well as transmission electron microscopy (TEM). Characterization of green synthesized nanoparticles demonstrated a UV–visible peak at 273 nm. Particle size was analysed from TEM monograph in the range of 69–108 nm which validates formation of nanoparticles. The in-vitro anticancer activity was done against A549 (IC50 = 4.70 μg/mL) and MCF7 (IC50 = 3.77 μg/mL) cell line. The biocompatibility assay of these nanoparticles was done on HEK–293 cell line (normal non-cancerous cells). Moreover, the effect of CuONPs on the lytic activity of HEWL was evaluated against Micrococcus lysodeikticus. Further, the interaction of CuONPs with hen egg white lysozyme (HEWL) at different temperature was investigated by steady state fluorescence spectroscopy. UV–visible and far ultra violet-circular dichroism (far UV-CD) spectroscopies were also employed to study the interaction of CuONPs with HEWL. All the results supported each other and show efficient binding between HEWL and CuONPs. The fluorescence emission study revealed that CuONPs quenches the fluorescence of HEWL involving dynamic quenching. The various binding parameters and structural disparity of HEWL in the presence of synthesised CuONPs were also calculated.

Porous tantalum structure integrated on Ti6Al4V base by Laser Powder Bed Fusion for enhanced bony-ingrowth implants: In vitro and in vivo validation

Despite the widespread application of Ti6Al4V and tantalum (Ta) in orthopedics, bioinertia and high cost limit their further applicability, respectively, and tremendous efforts have been made on the Ti6Al4V-Ta alloy and Ta coating to address these drawbacks. However, the scaffolds obtained are unsatisfactory. In this study, novel high-interface-strength Ti6Al4V-based porous Ta scaffolds were successfully manufactured using Laser Powder Bed Fusion for the first time, in which porous Ta was directly manufactured on a solid Ti6Al4V substrate. Mechanical testing revealed that the novel scaffolds were biomechanically compatible, and the interfacial bonding strength was as high as 447.5 MPa. In vitro biocompatibility assay, using rat bone marrow mesenchymal stem cells (r-BMSCs), indicated that the novel scaffolds were biocompatible. Alkaline phosphatase and mineralized nodule determination demonstrated that the scaffolds favored the osteogenic differentiation of r-BMSCs. Moreover, scaffolds were implanted into rabbits with femur bone defects, and imaging and histological evaluation identified considerable new bone formation and bone ingrowth, suggesting that the scaffolds were well integrated with the host bone. Overall, these results demonstrated good mechanical compatibility, biocompatibility, and osteointegration performance of the novel Ti6Al4V-based porous Ta scaffold, which possesses great potential for orthopedic clinical applications.

MO1046DOPING POLYSULFONE DIALYSIS MEMBRANES WITH HUMAN NEUTROPHIL ELASTASE INHIBITORS - A PILOT STUDY

Abstract Background and Aims During hemodialysis (HD) therapy, the long-term intradialytic contact of blood with large surfaced artificial materials (HD membranes) leads to continuous neutrophil activation, with the release of neutrophil elastase (NE), among other products. NE appears to contribute to enhance inflammation favoring the development of atherosclerosis, which is the main cause of mortality and morbidity in End-Stage Renal Disease patients. The modification of polysulfone (PSF) HD membranes by incorporating selective human NE inhibitors (NEIs) might reduce the inflammatory response and prevent HD associated complications. Thus, the present study aimed to dope PSF membranes with NEIs and assess their bioactivity and biocompatibility. Method As NEIs, it was used the commercially available Sivelestat (SIV), from Abcam, and an in house synthetized 4-oxo-β-lactam (D4L-3) based compound, selected from our library, and prepared as described elsewhere [1]. The PSF membranes were prepared according to [2] and further doped with each NEI by adsorption. Three independent assays were performed (in triplicates) where PSF membrane circles (2 cm in diameter) were incubated with ultrapure water (blank), NEIs vehicle (2.5% DMSO) or with 10 - 2000 nM SIV or D4L-3. The bioactivity of these modified PSF membranes was evaluated by a human NE activity assay [1]. The same method was used to determine the IC50 of both NEIs in solution. Biocompatibility assays (n = 3) were carried-out using duplicates of modified PSF membranes circles with Ø 2 cm incubated with 1.0 mL of whole-blood. After incubation, platelet (PLT) poor and PLT rich plasma were used to assess the levels of plasma hemoglobin (Hb) and PLT activation, respectively [2]. Results The IC50 of SIV and D4L-3 in solution were 30.9 and 87.6 nM, respectively. For PSF membranes doped with NEIs, their bioactivity increased in a concentration-dependent manner, with the highest NE inhibition of 44 and 22 % at 2000 nM SIV and D4L-3, respectively. The blank membranes showed the highest hemolytic capacity, whereas SIV and D4L-3 PSF membranes presented lower plasma Hb levels when compared with the blank or the vehicle; on average, SIV-PSF membranes presented 31% less plasma Hb than vehicle, while in D4L-3-PSF this decrease was of 51%. Regarding the thrombotic potential of these biomaterials, blank membranes presented slightly increased PLT activation levels when compared to vehicle, and modified SIV-PSF membranes showed, on average, 58% more PLT activation than the vehicle, while D4L-3-PSF membranes displayed 25% less, on average. Conclusion The successful adsorption of NEIs into PSF membranes was achieved and the NE inhibition ability was directly dependent on the concentration of the inhibitor utilized. Moreover, the bioactivity of SIV and D4L-3 when immobilized into PSF membranes it appears to follow their inhibitory capacity occurring in solution, with SIV showing a greater affinity for NE. However, concerning biocompatibility, D4L-3 displayed a greater safety performance than SIV, especially regarding the potential for triggering platelet activation. To ensure the applicability of these modified PSF membranes as a medical device, extensive further studies have to be carried-out by tweaking the conditions of the immobilization process in order to obtain an optimal equilibrium between bioactivity and biocompatibility, as well test new NEIs. Acknowledgments This work was supported by UIDB/50006/2020 and UIDB/04378/2020 with funding from FCT/MCTES through national funds, and by the project Dial4Life co-financed by FCT/MCTES (PTDC/MEC-CAR/31322/2017) and FEDER/COMPETE 2020 (POCI-01-0145-FEDER-031322).

Hyaluronic Acid and a Short Peptide Improve the Performance of a PCL Electrospun Fibrous Scaffold Designed for Bone Tissue Engineering Applications.

Bone tissue engineering is a rapidly developing, minimally invasive technique for regenerating lost bone with the aid of biomaterial scaffolds that mimic the structure and function of the extracellular matrix (ECM). Recently, scaffolds made of electrospun fibers have aroused interest due to their similarity to the ECM, and high porosity. Hyaluronic acid (HA) is an abundant component of the ECM and an attractive material for use in regenerative medicine; however, its processability by electrospinning is poor, and it must be used in combination with another polymer. Here, we used electrospinning to fabricate a composite scaffold with a core/shell morphology composed of polycaprolactone (PCL) polymer and HA and incorporating a short self-assembling peptide. The peptide includes the arginine-glycine-aspartic acid (RGD) motif and supports cellular attachment based on molecular recognition. Electron microscopy imaging demonstrated that the fibrous network of the scaffold resembles the ECM structure. In vitro biocompatibility assays revealed that MC3T3-E1 preosteoblasts adhered well to the scaffold and proliferated, with significant osteogenic differentiation and calcium mineralization. Our work emphasizes the potential of this multi-component approach by which electrospinning, molecular self-assembly, and molecular recognition motifs are combined, to generate a leading candidate to serve as a scaffold for bone tissue engineering.

In Vivo Study on Bone Response to 3D-Printed Constructs Designed from Microtomographic Images

The design of scaffolds that could adjust and adapt greatly to bone defects is a significant challenge to bone tissue engineering. Recently, 3D printing technology emerged as a process that could precisely control the architecture and design an exact geometry of the scaffold to the site or defect where it will be implanted. Thus, this research aimed to design and synthesize individualized constructs of polylactic acid (PLA) by 3D printing using microtomographic images to fit the edge of Wistar rat calvaria's critical size defects. The 3D-printed construct using the DICOM data of microtomographic images process to STL manipulated and designed by various software showed an excellent geometry. The in vitro biocompatibility assay of the 3D printing scaffold was evaluated by WST-1, showing an excellent biological response. Moreover, the in vivo evaluation of the bone regeneration process onto the rat calvaria defect model measured by the bone mineral density (BMD) at 8, 30, 60, and 90 days via micro-CT showed that at the end of the evaluation period, the 3D construct was integrated into the edges of the bone tissue, and new tissue deposited was in the process of mineralization. These findings suggest that the 3D construct matches the calvaria defect, allowing the novo mineral tissue to form. These individualized printed scaffolds may be a promising candidate in bone tissue engineering for future regeneration strategies.

Injectable and Degradable PEG Hydrogel with Antibacterial Performance for Promoting Wound Healing.

Injectable and degradable PEG hydrogel was prepared via Michael-type addition between cross-linking monomer 4-arm-PEG-MAL and two cross-linkers of hydrolysis degradable PEG-diester-dithiol and non-degradable PEG-dithiol, and it had a porous structure with the uniform pore size. The biocompatibility assays in vitro indicated that PEG hydrogel had excellent biocompatibility and can be degraded naturally without leading to any negative impact on cells. The results of antibacterial experiments showed that PEG hydrogel can inhibit the growth of bacteria. Furthermore, the Cell Counting Kit-8 (CCK-8) assay, LIVE/DEAD cell staining, and scratch healing experiments proved that PEG hydrogel can promote cell proliferation and migration, which had been further confirmed in in vivo experiments on the rat wound models. All experimental results demonstrated that PEG hydrogel is an injectable antibacterial dressing, which can promote the process of wound healing and has great potential in the field of wound healing.

Chromatic intervention and biocompatibility assay for biosurfactant derived from Balanites aegyptiaca (L.) Del

Extraction of biosurfactants from plants is advantageous than from microbes. The properties and robustness of biosurfactant derived from the mesocarp of Balanites aegyptiaca have been reported. However, the dark brown property of biosurfactant and lack of knowledge of its biocompatibility limits its scope. In the present work, the decolorization protocol for this biosurfactant was optimized using hydrogen peroxide. The hemolytic potential and biocompatibility based on cell toxicity and proliferation were also investigated. This study is the first report on the decolorization and toxicity assay of this biosurfactant. For decolorization of biosurfactant, 34 full factorial design was used, and the data were subjected to ANOVA. Results indicate that 1.5% of hydrogen peroxide can decolorize the biosurfactant most efficiently at 40 °C in 70 min at pH 7. Mitochondrial reductase (MTT) and reactive oxygen species (ROS) assays on M5S mouse skin fibroblast cells revealed that decolorized biosurfactant up to 50 µg/mL for 6 h had no significant toxic effect. Hemolysis assay showed ~ 2.5% hemolysis of human RBCs, indicating the nontoxic effect of this biosurfactant. The present work established a decolorization protocol making the biosurfactant chromatically acceptable. Biocompatibility assays confirm its safer use as observed by experiments on M5S skin fibroblast cells under in vitro conditions.

Synthesis, characterization and biological evaluation of N-Mannich base derivatives of 2-phenyl-2-imidazoline as potential antioxidants, enzyme inhibitors, antimicrobials, cytotoxic and anti-inflammatory agents

A series of N-Mannich base derivatives of 2-phenyl-2-imidazoline with substituted amines (1–13) were designed, synthesized, and characterized by spectroanalytical techniques. The newly synthesized compounds (SP1-SP13) were evaluated biologically for their antioxidant, α-amylase enzyme inhibition, antimicrobial, cytotoxic, and anti-inflammatory activities. Compounds were analyzed to predict their drug-likeliness behavior SP11 showed good activity in % FRSA against DPPH free radical at IC50 of 148.16 ± 2.81 µg/mL. SP11 and SP13 exhibited good antioxidant responses in TAC and TRP assays, respectively. SP2 has shown maximum % inhibition against α-amylase enzyme to 94.02 ± 0.2% at 200 µg/mL. SP2, SP8, and SP12 exhibited potent effect against α-amylase enzyme at IC50 value of 9.20 ± 0.48, 10.25 ± 0.43, and 13.81 ± 0.90 µg/mL, respectively. Compounds showed good to moderate activity against all bacterial and fungal strains. The compounds were selected for further analysis against hepatocellular carcinoma cell line (HepG2) based on LD50 and IC50 values obtained in brine shrimp cytotoxicity and biocompatibility assay, respectively. SP3, SP12, and SP13 were evaluated at 24, 48, and 72 h against HepG2 cells. Maximum response was observed at 72 h. A dose-optimization study was conducted and in vivo anti-inflammatory activity was performed on SP3, SP12, and SP13 based on results obtained from in vitro NO assay. The results are compared to that of standard (acetylsalicylic acid).

Covalently Bonded N-Acetylcysteine-polyester Loaded in PCL Scaffolds for Enhanced Interactions with Fibroblasts.

Poly(ε-caprolactone) (PCL) is commonly used in devices for tissue reconstruction due to its biocompatibility and suitable mechanical properties. However, its high crystallinity and hydrophobicity do not favor cell adhesion and difficult polymer bioresorption. To improve these characteristics, the development of engineered scaffolds for tissue regeneration, based on poly(globalide-co-ε-caprolactone) (PGlCL) covalently bonded with N-acetylcysteine (PGlCL-NAC) was proposed. The scaffolds were obtained from polymer blends of PCL and PGlCL-NAC, using the electrospinning technique. The use of PGlCL-NAC allowed for the modification of the physical and chemical properties of PCL electrospun scaffolds, including an expressive reduction in the fiber's diameter, hydrophobicity, and crystallinity. All electrospun scaffolds showed no cytotoxicity against fibroblasts (McCoy cells). In vitro biocompatibility assays showed that all tested scaffolds provided high cell viability and proliferation in short-term (NRU, MTT, and nuclear morphology assays) and long-term (clonogenic assay) assays. Nevertheless, PGlCL-NAC based scaffolds have favored the survival and proliferation of the cells in comparison to PCL scaffolds. Cell adhesion on the scaffolds assessed by electronic microscopy images confirmed this behavior. These results suggest that the incorporation of PGlCL-NAC in scaffolds for tissue regeneration could be a promising strategy to improve cell-surface interactions and contribute to the development of more efficiently engineered biomedical devices.

Gelatin hydrogel/contact lens composites as rutin delivery systems for promoting corneal wound healing

Corneal wound healing is a highly regulated biological process that is of importance for reducing the risk of blinding corneal infections and inflammations. Traditional eye drop was the main approach for promoting corneal wound healing. However, its low bioavailability required a high therapeutic concentration, which can lead to ocular or even systemic side effects. To develop a safe and effective method for treating corneal injury, we fabricated rutin-encapsulated gelatin hydrogel/contact lens composites by dual crosslinking reactions including in situ free radical polymerization and carboxymethyl cellulose/N-hydroxysulfosuccinimide crosslinking. In vitro drug release results evidenced that rutin in the composites could be sustainedly released for up to 14 days. In addition, biocompatibility assay indicated nontoxicity of the composites. Finally, the effect of rutin-encapsulated composites on the healing of the corneal injury in rabbits was investigated. The injury was basically cured in corneas using rutin-encapsulated composites (healing rate, 98.3% ± 0.7%) at 48 h post-operation, while the damage was still present in corneas using the composite (healing rate, 87.0% ± 4.5%). Further proteomics analysis revealed that corneal wound healing may be promoted by the ERK/MAPK and PI3K/AKT signal pathways. These results inform a potential intervention strategy to facilitate corneal wound healing in humans.

Phytofabrication of cobalt oxide nanoparticles from Rhamnus virgata leaves extract and investigation of different bioactivities.

The tunable cobalt oxide nanoparticles (CoONPs) are produced due to the phytochemicals present in Rhamnus virgata (RhV) leaf extract which functions as reducing and stabilization agents. The synthesis of CoONPs was confirmed using different analytical techniques: UV-Vis spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), dynamics light scatterings (DLS), Fourier-transform infrared spectroscopy (FTIR), energy dispersive X-ray, and Raman spectroscopy analyses. Furthermore, multiple biological activities were performed. Significant antifungal and antibacterial potentials have been reported. The in vitro cytotoxic assays of CoONPs revealed strong anticancer activity against human hepatoma HUH-7 (IC50 : 33.25 μg/ml) and hepatocellular carcinoma HepG2 (IC50 : 11.62 μg/ml) cancer cells. Dose-dependent cytotoxicity potency was confirmed against Leishmania tropica (KMH23 ); amastigotes (IC50 : 58.63 μg/ml) and promastigotes (IC50 : 32.64 μg/ml). The biocompatibility assay using red blood cells (RBCs; IC50 : 4,636 μg/ml) has confirmed the bio-safe nature of CoONPs. On the whole, results revealed nontoxic nature of RhV-CoONPs with promising biological potentials.