Viability Of Fibroblast Cells Research Articles

Extrusion-based bioprinting: considerations toward gelatin-alginate bioink

Purpose This study aims to develop a simplified bioink preparation method that can be applied to most hydrogel bioinks used in extrusion-based techniques. Design/methodology/approach The parameters of the bioprinting process significantly affect the printability of the bioink and the viability of cells. In turn, the bioink formulation and its physicochemical properties may influence the appropriate range of printing parameters. In extrusion-based bioprinting, the rheology of the bioink affects the printing pressure, cell survival and structural integrity. Three concentrations of alginate-gelatin hydrogel were prepared and printed at three different flow rates and nozzle gauges to investigate the print parameters. Other characterizations were performed to evaluate the hydrogel structure, printability, gelation time, swelling and degradation rates of the bioink and cell viability. An experimental design was used to determine optimal parameters. The analyses included live/dead assays, rheological measurements, swelling and degradation. Findings The experimental design results showed that the hydrogel flow rate substantially influenced printing accuracy and pressure. The best hydrogel flow rate in this study was 10 ml/h with a nozzle gauge of 18% and 4% alginate. Three different concentrations of alginate-gelatin hydrogels were found to exhibit shear-thinning behavior during printing. After seven days, 46% of the structure in the 4% alginate-5% gelatin sample remained intact. After printing, the viability of skin fibroblast cells for the optimized sample was 91%. Originality/value This methodology offers a straightforward bioink preparation method applicable to the majority of hydrogels used in extrusion-based procedures. This can also be considered a prerequisite for cell printing.

Investigating the Viability of Human Gingival Fibroblast Cells in a Polyhydroxybutyrate/Chitosan/Bioglass Nanoparticles Scaffold

Background: The primary method for addressing dental problems traditionally involves the removal and replacement of damaged tissue with synthetic substitutes. However, these materials often lack the physical and chemical properties of natural teeth and are prone to mechanical failures. Recent advancements in tissue engineering have highlighted an alternative approach that allows for the regeneration of teeth using scaffolds. Objectives: This study explored the viability of human gingival fibroblast cells in a scaffold composed of polyhydroxybutyrate, chitosan, and bioglass nanoparticles (PHB/chitosan/nBG). Methods: This study is experimental and was conducted in a laboratory setting. Scaffolds of PHB, PHB/chitosan, and PHB/chitosan/nBG were previously prepared from PHB polymer, chitosan, and bioglass using the electrospinning method. Human gingival fibroblast cells (C165) were acquired from the Pasteur Institute and cultured. Twenty thousand cells were seeded onto each scaffold and into the wells of a 24-well plate for periods of 3, 5, and 7 days. Subsequently, cell viability and proliferation were assessed using the MTT assay method, with each experiment repeated three times. Results: Cell viability and proliferation on the PHB/chitosan/nBG scaffold demonstrated a significant increase compared to the other scaffolds (P ≤ 0.01). Conclusions: The PHB/chitosan/nBG scaffold was found to be non-toxic to human gingival fibroblast cells and exhibited good biocompatibility.

Comparative Cytotoxicity of Menthol and Eucalyptol: An In Vitro Study on Human Gingival Fibroblasts.

The aim of this study was to assess the influence of eucalyptol and menthol on the cell viability, migration, and reactive oxygen species production of human gingival fibroblasts (GFs) in vitro. Three different concentrations of eucalyptol and menthol were prepared following ISO 10993-5 guidelines (1, 5, and 10 mM). GFs were isolated from extracted teeth from healthy donors. The following parameters were assessed: cell viability via MTT, Annexin-V-FITC and 7-AAD staining, and IC50 assays; cell migration via horizontal scratch wound assay; and cell oxidative stress via reactive oxygen species assay. Data were analyzed using one-way ANOVA and Tukey's post hoc test. Statistical significance was established at p < 0.05. Eucalyptol and Menthol exhibited high cytotoxicity on gingival fibroblasts, as evidenced by cytotoxicity assays. Eucalyptol showed lower levels of cytotoxicity than menthol, compared to the control group. The cytotoxicity of the tested substances increased in a concentration-dependent manner. The same occurred in a time-dependent manner, although even 10 min of exposure to the tested substances showed a high cytotoxicity to the GFs. Commercially available products for oral application with these substances in their composition should be tested for cytotoxicity before their use.

Levofloxacin loaded poly (ethylene oxide)-chitosan/quercetin loaded poly (D,L-lactide-co-glycolide) core-shell electrospun nanofibers for burn wound healing.

This study developed a new burn wound dressing based on core-shell nanofibers that co-deliver antibiotic and antioxidant drugs. For this purpose, poly(ethylene oxide) (PEO)-chitosan (CS)/poly(D,L-lactide-co-glycolide) (PLGA) core-shell nanofibers were fabricated through co-axial electrospinning technique. Antibiotic levofloxacin (LEV) and antioxidant quercetin (QS) were incorporated into the core and shell parts of PEO-CS/PLGA nanofibers, respectively. The drugs could bond to the polymer chains through hydrogen bonding, leading to their steady release for 168h. An in vitro drug release study showed a burst effect followed by sustained release of LEV and QS from the nanofibers due to the Fickian diffusion. The NIH 3T3 fibroblast cell viability of the drug loaded core-shell nanofibers was comparable to that in the control (tissue culture polystyrene) implying biocompatibility of the nanofibers and their cell supportive role. However, there was no significant difference in cell viability between the drug loaded and drug free core-shell nanofibers. According to in vivo experiments, PEO-CS-LEV/PLGA-QS core-shell nanofibers could accelerate the healing process of a burn wound compared to a sterile gauze. Thanks to the synergistic therapeutic effect of LEV and QS, a significantly higher wound closure rate was recorded for the drug loaded core-shell nanofibrous dressing than the drug free nanofibers and control. Conclusively, PEO-CS-LEV/PLGA-QS core-shell nanofibers were shown to be a promising wound healing material that could drive the healing cascade through local co-delivery of LEV and QS to burn wounds.

Laser texturing and oxidation of TiZrTa thin films to improve the biocompatible performance of titanium alloys

Titanium (Ti) and Ti alloys possess extensive applications in the medical field due to their non-toxic, biocompatible, and antibacterial properties. This study investigates the biocompatibility enhancement of a Ti-based alloy, Ti-6Al-4V, through a multi-step process involving cathodic arc ion plating of a TiZrTa thin film and subsequent laser-textured oxidation (LTO). LTO treatment produced a structured microtopography with regular groove patterns, including straight lines (L-s), circles (L-c), and checkboards (L-ch), resulting in surface oxidation and the formation of various oxides on the TiZrTa coating. Microstructure analyses revealed substantial alterations in surface topography induced by laser texturing. Antibacterial assessments against Staphylococcus aureus (S. aureus) showed that the films with LTO treatment did not exhibit significant advantages after 12 or 24 h of coculture because the laser-textured portions consisted of a combination of the film and the substrate, and the antibacterial effect was not obvious. Coatings with LTO treatment significantly improved L-929 mouse fibroblasts cell viability at 48 h, particularly for samples with a 50 μm spacing of straight and circular patterns (L-s and L-c). After two weeks of MG-63 human osteosarcoma cell culture, the viability of all samples reached similar levels. It suggested that the TiZrTa-coated Ti-6Al-4V exhibited good biocompatibility with both cells. This study contributed to the understanding of surface modification techniques for enhancing the biocompatibility of Ti-based alloys in biomedical applications.

Development and in vitro characterization nanoemulsion containing the methanol extract of Hypericum linarioides for wound healing: In vitro scratch assay

It was aimed to develop and in vitro characterize the methanol extract of Hypericum linarioides (MHL)-containing nanoemulsion formulation (MHL-NEF) to heal the wound effectively. MHL-NEF was prepared and its droplet size, polydispersity index (PDI), viscosity, pH and zeta potential (ZP) values were determined. The effect of MHL and MHL-NEF on human dermal fibroblast cell viability was examined by MTT assay. Also, their wound healing potential was evaluated using the scratch assay. The droplet size, PDI, ZP, pH and viscosity values for the MHL-NEF were found to be 157.67±7.61 nm, 0.268±0.036, (-)40.20±6.79 mV, 4.27±0.01, and 1.82±0.01 cP, respectively. In the cell viability assay, the highest percentage of living cells was obtained at concentration of 0.4 µg/mL for the MHL and MHL-NEF. In the scratch assay, MHL-NEF showed significantly ameliorated wound closure (%) rates at 24 and 30 h than the groups of control, MHL and blank-NEF (NEF without MHL) (p < 0.001). Immunofluorescence staining was carried out. TGF-β1 and FGFR-2 expressions in MHL-NEF-treated fibroblast cells increased significantly at 24 h compared to the groups of control, MHL, and B-NEF (p < 0.001). Our findings show that MHL-NEF may be promising for better wound healing.

Combination of stem cell-derived secretome from human exfoliated deciduous teeth with Yemeni Sidr honey on cell viability and migration: an in vitro study

IntroductionBone diseases have a profound global impact, especially when the body’s innate regenerative capacity falls short in the face of extensive damage. Stem cells from human exfoliated deciduous teeth (SHEDs), discovered in 2003, offer a promising solution for tissue repair, as they self-renew naturally and are easily obtainable. Mesenchymal stem cells (MSCs), including SHEDs, are believed to promote tissue regeneration by releasing growth factors, collectively known as the secretome.AimsThis study explored the potential of combining SHED-derived secretome with Yemeni Sidr honey to improve osteoblast and fibroblast cell viability and migration.Materials and methodsThe experiment involved treating cell cultures of two types of rat cell lines - 7F2 osteoblast and BHK-21 fibroblast immortalized cells - with SHED-derived secretome and Yemeni Sidr honey. After the treatment, cell viability was measured using the MTT assay, which calculates OD at 590 nm. Additionally, the scratch assay was conducted to evaluate cell migration, and ImageJ software was used for data processing.ResultsThe findings indicated that combining SHED-derived secretome and Yemeni Sidr honey enhanced osteoblast and fibroblast cell viability and migration. Furthermore, the study highlighted the difference in the stimulative potential of SHED-derived secretome, Yemeni Sidr honey, and their combination, on the viability and migration of the cultured cells.ConclusionThe research concludes that combining SHED-derived secretome with Yemeni Sidr honey has the potential to promote cell viability and migration in in-vitro settings. The synergistic application of these substances has been found to be more effective -when combined in a dose-dependent manner- than their counterparts. Overall, the current study serves as a foundation for further investigations to establish if the explored substance has any useful clinical applications.

Morroniside improves AngII-induced cardiac fibroblast proliferation, migration, and extracellular matrix deposition by blocking p38/JNK signaling pathway through the downregulation of KLF5.

Myocardial fibrosis (MF), which is an inevitable pathological manifestation of many cardiovascular diseases in the terminal stage, often contributes to severe cardiac dysfunction and sudden death. Morroniside (MOR) is the main active component of Cornus officinalis with a variety of biological activities. This study was designed to explore the efficacy of MOR in MF and to investigate its pharmacological mechanism. The viability of MOR-treated human cardiac fibroblast (HCF) cells with or without Angiotensin II (AngII) induction was assessed with Cell Counting Kit-8 (CCK-8). The migration of AngII-induced HCF cells was appraised with a transwell assay. Gelatin zymography analysis was adopted to evaluate the activities of MMP2 and MMP9, while immunofluorescence assay was applied for the estimation of Collagen I and Collagen III. By means of western blot, the expressions of migration-, fibrosis-, and p38/c-Jun N-terminal kinase (JNK) signal pathway-related proteins were resolved. The transfection efficacy of oe-Kruppel-like factor 5 (KLF5) was examined with reverse transcription-quantitative PCR (RT-qPCR) and western blot. In this study, it was found that MOR treatment inhibited AngII-induced hyperproliferation, migration, and fibrosis of HCF cells, accompanied with decreased activities of matrix metalloproteinase 2 (MMP2), matrix metalloproteinase 9 (MMP9), connective tissue growth factor (CTGF), Fibronectin, and α-SMA, which were all reversed by KLF5 overexpression. Collectively, MOR exerted protective effects on MF by blocking p38/JNK signal pathway through the downregulation of KLF5.

Potential Wound Dressing with Antibacterial Effect from Cross‐Linked Polyvinyl Alcohol/Sodium Caseinate/CuO NP Electrospun Mat

AbstractIn this study, nanofibers were produced from Polyvinyl alcohol (PVA)/Sodium Caseinate (SoCAS)/Copper Oxide nanoparticle (CuO NP) mixtures by electrospinning method. Nano surfaces were cross‐linked by immersion in a Glutaraldehyde (GLA) bath. Electrospun mats are designed as modern wound dressings with antibacterial effects for exuding wounds. The cross‐linking process by dipping has thickened a bit of nanofiber diameter by creating a coating effect on fiber surface. The increase of acetal bonds and decrease of hydroxyl groups in structure by cross‐linking have improved thermal properties of nanofibers. The increase in melting enthalpy has also improved mechanical properties of mats. The mixture of semicrystalline PVA and SoCAS has increased breaking stress of nanostructure. Besides, the CuO NP additive improved the breaking strength and elongation behavior of mats. It was stated that cross‐linked nanofibers swelled without dissolving in distilled water and contained water‐repellent groups. The CuO NP supplementation delayed the growth of Escherichia coli (E. coli). However, it was observed that antibacterial effect against Staphylococcus aureus (S. aureus) was higher than against E. coli. It was reported that 5 % CuO NP‐doped nanofiber can be used as a wound dressing, owing to its high fibroblast cell viability at 24th and 48th hours and 99.48 % antibacterial activity against S. aureus.

Toward Enhanced Antioxidant and Protective Potential: Conjugation of Corn Cob Xylan with Gallic Acid as a Novel Approach.

Maize ranks as the second most widely produced crop globally, yielding approximately 1.2 billion tons, with corn cob being its primary byproduct, constituting 18 kg per 100 kg of corn. Agricultural corn production generates bioactive polysaccharide-rich byproducts, including xylan (Xyl). In this study, we used the redox method to modify corn cob xylan with gallic acid, aiming to enhance its antioxidant and protective capacity against oxidative stress. The conjugation process resulted in a new molecule termed conjugated xylan-gallic acid (Xyl-GA), exhibiting notable improvements in various antioxidant parameters, including total antioxidant capacity (1.4-fold increase), reducing power (1.2-fold increase), hydroxyl radical scavenging (1.6-fold increase), and cupric chelation (27.5-fold increase) when compared with unmodified Xyl. At a concentration of 1 mg/mL, Xyl-GA demonstrated no cytotoxicity, significantly increased fibroblast cell viability (approximately 80%), and effectively mitigated intracellular ROS levels (reduced by 100%) following oxidative damage induced by H2O2. Furthermore, Xyl-GA exhibited non-toxicity toward zebrafish embryos, offered protection against H2O2-induced stress, and reduced the rate of cells undergoing apoptosis resulting from H2O2 exposure. In conclusion, our findings suggest that Xyl-GA possesses potential therapeutic value in addressing oxidative stress-related disturbances. Further investigations are warranted to elucidate the molecular structure of this novel compound and establish correlations with its pharmacological activities.

Elevated KDM4D Expression in Pterygium: Impact and Potential Inhibition by Lycium Barbarum Polysaccharide.

Purpose: This study aimed to explore the effects of elevated KDM4D expression and potential therapeutic effects of Lycium barbarum polysaccharide (LBP) on pterygium. Methods: The expression levels of KDM4D in the primary pterygium (n = 29) and normal conjunctiva (n = 14) were detected by immunohistochemistry. The effects of KDM4D on pterygium fibroblasts were detected by the CCK-8 assay, liquid chromatography-mass spectrometry assay, flow cytometry, and scratch wound healing assay. The relative expression of KDM4D in pterygium fibroblasts stimulated by interleukin (IL)-1β, IL-6, IL-8, and LBP was detected by quantitative real-time PCR and Western blot. The effects of LBP on pterygium fibroblasts were detected using flow cytometry and scratch wound healing assays. Results: The expression level of KDM4D in pterygium was higher than that in normal conjunctiva. KDM4D increased the cell viability of pterygium fibroblasts. The differentially expressed genes identified in the LM-MS assay enriched in "actin filament organization" and "apoptosis." KDM4D promoted migration and inhibited apoptosis of pterygium fibroblasts in vitro. Inflammatory cytokines, including IL-1β, IL-6, and IL-8, enhanced the expression of KDM4D in pterygium fibroblasts. LBP inhibited the expression of KDM4D in pterygium fibroblasts and decreased their cell viability. Moreover, LBP attenuated the KDM4D effects on migration and apoptosis of pterygium fibroblasts. Conclusions: Elevated KDM4D expression is a risk factor for pterygium formation. LBP inhibits the expression of KDM4D in pterygium fibroblasts and may be a potential drug for delaying pterygium development.

Method to obtain a plasma rich in platelet- and plasma-growth factors based on water evaporation.

Platelet-Rich Plasma, also known as PRP, is an autologous biologic product used in medicine as a treatment for tissue repair. Nowadays, the majority of PRP obtention methods enrich only platelets, not considering extraplatelet biomolecules, which take part in several cell processes. In the present work, a novel PRP preparation method was developed to obtain a PRP rich in both platelet and plasma extraplatelet molecules. The method is based on the evaporation of the water of the plasma using a rotary evaporator. With this new methodology an increase in plasmatic growth factors and, as a consequence, a better dermal fibroblast cell viability was achieved, compared to a standard PRP formulation. This novel PRP product obtained with this new methodology showed promising results in vitro as an improved PRP treatment in future application.

In situ sono-rheometric assessment of procaine-loaded calcium pectinate hydrogel for enhanced drug releasing under ultrasound stimulation

Ultrasound (US) triggered alterations in the viscoelastic behavior of the procaine-loaded ionically gelatinized pectin hydrogel matrix, and drug release was observed using a sono-device rheometer. The gel softened immediately upon activation of the ultrasound operated at 43 kHz and remained in a softened state throughout the irradiation. Upon cessation of ultrasound, the gel promptly reverted to its original hardness. This cycle of softening was consistently observed in ionically crosslinked pectin hydrogels, resulting in the promotion of procaine release, particularly with higher US power and lower calcium concentration. As the amount of loaded procaine increased, the gel weakened due to ion exchange with the calcium crosslinker and procaine. The most substantial release efficiency, reaching 82 % with a concentration of 32 μg/ml, was achieved when the hydrogels contained 0.03 % procaine within the gelatinized hydrogel medicine at a calcium concentration of 0.9 M, representing a six-fold increase compared to that without US. Notably, US exposure affected the 3D porous structure and degradation rate, leading to hydrogel collapse and facilitating medicine release. Additionally, the procaine-loaded pectin hydrogels with 0.9 M calcium exhibited improved fibroblast cell viability, indicating non-toxicity compared to those hydrogels prepared at a higher Ca2+ concentration of 2.4 M.

Water-soluble intracellular extract of Desmodesmus sp. YT enhanced the antioxidant capacity of human skin fibroblast to protect the skin from UV damage.

The oxidative stress induced by ultraviolet (UV) radiation is a pivotal factor in skin aging and can even contribute to the development of skin cancer. This study explored the antioxidant effect and mechanism of water-soluble intracellular extract (WIE) of Desmodesmus sp.YT (YT), aiming to develop a natural antioxidant suitable for incorporation into cosmetics. The study evaluated the scavenging capacity of YT-WIE against free radicals and assessed its impact on human skin fibroblasts (HSF) cell viability and UV resistance using Cell Counting Kit-8 (CCK-8). Transcriptome sequencing was employed to elucidate the mechanism of action, while RT-qPCR and western blot were used to validate the expression of key genes. YT-WIE displayed robust antioxidant activity, demonstrating potent scavenging abilities against 2,2-diphenyl-1-picrylhydrazyl (DPPH; IC50 = 0.55 mg mL-1), 2,2'-Azino-bis (3 ethylbenzothiazoline-6-sulfonic acid; ABTS; IC50 = 3.11 mg mL-1), Hydroxyl (·OH; IC50 = 2.21 mg mL-1), and Superoxide anion (O2 •-; IC50 = 0.98 mg mL-1). Furthermore, compared to the control group, the YT-WIE group exhibited an 89.30% enhancement in HSF viability and a 44.63% increase in survival rate post-UV irradiation. Significant upregulation of antioxidant genes (GCLC, GCLM, TXNRD1, HMOX1, NQO1) was observed with YT-WIE treatment at 400 μg mL-1, with fold increases ranging from 1.13 to 5.85 times. YT-WIE demonstrated considerable potential as an antioxidant, shielding human cells from undue oxidative stress triggered by external stimuli such as UV radiation. This suggests its promising application in cosmetics antioxidants.

Electrospun Nanofibers Encapsulated with Natural Products: A Novel Strategy to Counteract Skin Aging.

The skin is the primary tissue affected by wounds and aging, significantly impacting its protective function. Natural products are widely used in cosmetics, representing a new approach to preventing age-related damage. Nanomedicine combines nanotechnology and traditional treatments to create innovative drugs. The main targets of nanotechnological approaches are wound healing, regeneration, and rejuvenation of skin tissue. The skin barrier is not easily permeable, and the creation of modern nanodevices is a way to improve the passive penetration of substances. In this study, Helichrysum italicum oil (HO) was combined with different types of electrospun nanofibers to study their protective activity on the skin and to evaluate their future application for topical treatments. In the present research, we used biodegradable polymers, including polyvinyl alcohol (PVA) and polyvinylpyrrolidone (PVP), which were characterized by a scanning electron microscope (SEM). All results show a positive trend in cell proliferation and viability of human skin stem cells (SSCs) and BJ fibroblasts pre-treated with combined nanofibers and then exposed to UV stress. Gene expression analysis revealed the activation of a molecular rejuvenation program in SSCs treated with functionalized nanofibers before UV exposure. Understanding the mechanisms involved in skin changes during aging allows for the future application of nanomaterials combined with HO directly to the patients.

Optimization of hybrid gelatin-polysaccharide bioinks exploiting thiol-norbornene chemistry using a reducing additive

Thiol-norbornene chemistry offers great potential in the field of hydrogel development, given its step growth crosslinking mechanism. However, limitations exist with regard to deposition-based bioprinting of thiol-containing hydrogels, associated with premature crosslinking of thiolated (bio)polymers resulting from disulfide formation in the presence of oxygen. More specifically, disulfide formation can result in an increase in viscosity thereby impeding the printing process. In the present work, hydrogels constituting norbornene-modified dextran (DexNB) combined with thiolated gelatin (GelSH) are selected as case study to explore the potential of incorporating the reducing agent tris(2-carboxyethyl)phosphine (TCEP), to prevent the formation of disulfides. We observed that, in addition to preventing disulfide formation, TCEP also contributed to premature, spontaneous thiol-norbornene crosslinking without the use of UV light as evidenced via 1H-NMR spectroscopy. Herein, an optimal concentration of 25 mol% TCEP with respect to the amount of thiols was found, thereby limiting auto-gelation by both minimizing disulfide formation and spontaneous thiol-norbornene reaction. This concentration results in a constant viscosity during at least 24 h, a more homogeneous network being formed as evidenced using atomic force microscopy while retaining bioink biocompatibility as evidenced by a cell viability of human foreskin fibroblasts exceeding 70% according to ISO 10993-6:2016.

A Combination of Curcumin and Lactobacillus rhamnosus GG Inhibits Viability and Induces Apoptosis in SCC-9 Human Oral Squamous Cell Carcinoma Cells.

The aim of this study was to evaluate the effect of curcumin combined with Lactobacillus rhamnosus GG cell-free supernatant (LGG CFS) on the proliferation and induction of apoptosis in SCC-9 oral squamous cell carcinoma (OSCC) cells. Curcumin (40 µg/ml) and 25% v/v LGG CFS (108 CFU/ml), both alone and in a combination regimen, significantly decreased the viability of SCC-9 cells and normal human gingival fibroblast (HGF) cells. Interestingly, the combination of low doses of curcumin (5 µg/ml) and 25% v/v LGG CFS (106 CFU/ml) had no effect on the HGF cells but significantly inhibited the viability of SCC-9 cells (p < 0.05). Flow cytometric analysis revealed that SCC-9 cells treated with the combination of low-dose curcumin and low-dose LGG CFS had a higher apoptotic rate than the cells in the control group and the single treatment groups (p < 0.05). The combined treatment also significantly increased the Bax/Bcl2 mRNA and protein expression in SCC-9 cells (p < 0.05) but not in HGF cells, indicating the underlying mechanism of the combination regimen. There was no significant difference in caspase-3 protein expression or the Bcl-xL/Bak and Mcl-1/Bak ratios between the treatment and control groups in both cell lines. These findings suggested that the coadministration of curcumin and LGG could exhibit anticancer effects in SCC-9 cells without causing toxicity to normal fibroblast cells.

A Study on Thiol-Michael Addition to Semi-Synthetic Elastin-Hyaluronan Material for Electrospun Scaffolds.

Thiol-Michael addition is a chemical reaction extensively used for conjugating peptides to polysaccharides with applications as biomaterials. In the present study, for designing a bioactive element in electrospun scaffolds as wound dressing material, a chemical strategy for the semi-synthesis of a hyaluronan-elastin conjugate containing an amide linker (ELAHA) was developed in the presence of tris(2-carboxyethyl)phosphine hydrochloride (TCEP ⋅ HCl). The bioconjugate was electrospun with poly-D,L-lactide (PDLLA), obtaining scaffolds with appealing characteristics in terms of morphology and cell viability of dermal fibroblast cells. For comprehending the factors influencing the efficiency of the bioconjugation reaction, thiolated amino acids were also investigated as nucleophiles toward hyaluronan decorated with Michael acceptors in the presence of TCEP ⋅ HCl through the evaluation of byproducts formation.

Fluorescent Graphitic Carbon Nitride (g-C3N4)-Embedded Hyaluronic Acid Microgel Composites for Bioimaging and Cancer-Cell Targetability as Viable Theragnostic.

Fluorescent graphitic carbon nitride (g-C3N4) doped with various heteroatoms, such as B, P, and S, named Bg-C3N4, Pg-C3N4, and Sg-C3N4, were synthesized with variable band-gap values as diagnostic materials. Furthermore, they were embedded within hyaluronic acid (HA) microgels as g-C3N4@HA microgel composites. The g-C3N4@HA microgels had a 0.5-20 μm size range that is suitable for intravenous administration. Bare g-C3N4 showed excellent fluorescence ability with 360 nm excitation wavelength and 410-460 emission wavelengths for possible cell imaging application of g-C3N4@HA microgel composites as diagnostic agents. The g-C3N4@HA-based microgels were non-hemolytic, and no clotting effects on blood cells or cell toxicity on fibroblasts were observed at 1000 μg/mL concentration. In addition, approximately 70% cell viability for SKMEL-30 melanoma cells was seen with Sg-C3N4 and its HA microgel composites. The prepared g-C3N4@HA and Sg-C3N4@HA microgels were used in cell imaging because of their excellent penetration capability for healthy fibroblasts. Furthermore, g-C3N4-based materials did not interact with malignant cells, but their HA microgel composites had significant penetration capability linked to the binding function of HA with the cancerous cells. Flow cytometry analysis revealed that g-C3N4 and g-C3N4@HA microgel composites did not interfere with the viability of healthy fibroblast cells and provided fluorescence imaging without any staining while significantly decreasing the viability of cancerous cells. Overall, heteroatom-doped g-C3N4@HA microgel composites, especially Sg-C3N4@HA microgels, can be safely used as multifunctional theragnostic agents for both diagnostic as well as target and treatment purposes in cancer therapy because of their fluorescent nature.

Optimization of a Photobiomodulation Protocol to Improve the Cell Viability, Proliferation and Protein Expression in Osteoblasts and Periodontal Ligament Fibroblasts for Accelerated Orthodontic Treatment.

Numerous pieces of evidence have supported the therapeutic potential of photobiomodulation (PBM) to modulate bone remodeling on mechanically stimulated teeth, proving PBM's ability to be used as a coadjuvant treatment to accelerate orthodontic tooth movement (OTM). However, there are still uncertainty and discourse around the optimal PBM protocols, which hampers its optimal and consolidated clinical applicability. Given the differential expression and metabolic patterns exhibited in the tension and compression sides of orthodontically stressed teeth, it is plausible that different types of irradiation may be applied to each side of the teeth. In this sense, this study aimed to design and implement an optimization protocol to find the most appropriate PBM parameters to stimulate specific bone turnover processes. To this end, three levels of wavelength (655, 810 and 940 nm), two power densities (5 and 10 mW/cm2) and two regimens of single and multiple sessions within three consecutive days were tested. The biological response of osteoblasts and periodontal ligament (PDL) fibroblasts was addressed by monitoring the PBM's impact on the cellular metabolic activity, as well as on key bone remodeling mediators, including alkaline phosphatase (ALP), osteoprotegerin (OPG) and receptor activator of nuclear factor κ-B ligand (RANK-L), each day. The results suggest that daily irradiation of 655 nm delivered at 10 mW/cm2, as well as 810 and 940 nm light at 5 mW/cm2, lead to an increase in ALP and OPG, potentiating bone formation. In addition, irradiation of 810 nm at 5 mW/cm2 delivered for two consecutive days and suspended by the third day promotes a downregulation of OPG expression and a slight non-significant increase in RANK-L expression, being suitable to stimulate bone resorption. Future studies in animal models may clarify the impact of PBM on bone formation and resorption mediators for longer periods and address the possibility of testing different stimulation periodicities. The present in vitro study offers valuable insights into the effectiveness of specific PBM protocols to promote osteogenic and osteoclastogenesis responses and therefore its potential to stimulate bone formation on the tension side and bone resorption on the compression side of orthodontically stressed teeth.