Low Molecular Weight Hyaluronic Acid Effect on Dental Pulp Stem Cells In Vitro

A Cerium Oxide Loaded Hyaluronic Acid Nanosystem Remits Glucose Oxidative Stress-Induced Odontoblasts Mitochondrial Apoptosis through Regulation of PGAM5 Pathway

Diabetes mellitus (DM) induced mitochondrial oxidative stress (OS) can lead to severe injury of dental pulp. The cerium oxide nanoparticles (CNP) have been proven to have excellent antioxidative activity. However, whether CNP can relieve dental pulp damage caused by DM and the underlying mechanisms remain unclear. In this study, we modified ceria with hyaluronic acid to prepare nanoceria with good biocompatibility, water solubility, and stability, namely, HACNP (hyaluronic acid cerium oxide nanoparticles). We demonstrated the protective effect of HACNP on diabetic OS-induced mitochondrial apoptosis in dental pulp-like cells. As far as the mechanism of action was concerned, glucose oxidase (GO) treatment promoted the activation of phosphoglycerate mutase family 5 (PGAM5) leading to mitochondrial abnormalities and apoptosis in an odontoblast-like cell line (mDPC6T). Knockdown or overexpression of PGAM5 further validate these results. Meanwhile, HACNP remitted GO-related toxicity via down-regulating PGAM5 expression, whereas overexpression of PGAM5 abolished the beneficial effect of HACNP. Furthermore, in the constructed animal research model of diabetic pulp injury, we also confirmed that HACNP alleviated apoptosis and mitochondrial injury of dental pulp and decreased the expression level of PGAM5 in diabetic pulp tissue. In conclusion, these results revealed that HACNP played a protective role on diabetes-associated dental pulp injury through targeting the PGAM5-mediated mitochondrial pathway, providing an idea and method for the prevention or treatment of diabetes-induced dental pulp damage.

Bovine pulp extracellular matrix hydrogel for regenerative endodontic applications: in vitro characterization and in vivo analysis in a necrotic tooth model

BACKGROUND

Regenerative endodontic procedures (REPs) offer the promise of restoring vitality and function to a previously necrotic and infected tooth. However, the nature of regenerated tissues following REPs remains unpredictable and uncontrollable. Decellularized extracellular matrix scaffolds have gained recent attention as scaffolds for regenerative endodontics.

OBJECTIVES

Preparation and characterization of a bovine dental pulp-derived extracellular matrix (P-ECM) hydrogel for regenerative endodontic applications. Biocompatibility and regenerative capacity of the prepared scaffold were evaluated in vivo in a canine animal model.

METHODS

Fifteen freshly extracted bovine molar teeth were used to prepare P-ECM hydrogels following approval of the institutional review board of the faculty of dentistry, Alexandria University. Decellularization and lyophilization of the extracted pulp tissues, DNA quantification and histological examination of decellularized P-ECM were done. P-ECM hydrogel was prepared by digestion of decellularized pulps. Prepared scaffolds were evaluated for protein content and release as well as release of VEGF, bFGF, TGF-β1 and BMP2 using ELISA. Rabbit dental pulp stem cells' (rDPSCs) viability in response to P-ECM hydrogels was performed. Finally, proof-of-concept of the regenerative capacity of P-ECM scaffolds was assessed in an infected mature canine tooth model following REPs versus blood clot (BC), injectable platelet-rich fibrin (i-PRF) or hyaluronic acid (HA). Statistical analysis was done using independent t test, the Friedman test and chi-square tests (p value ≤ 0.05).

RESULTS

DNA was found to be below the cut-off point (50 ng/mg tissue). Histological evaluation revealed absence of nuclei, retention of glycosaminoglycans (GAGs) and collagen content, respectively. P-ECM hydrogel had a total protein content of (493.12 µg/µl) and protein release was detected up to 14 days. P-ECM hydrogel also retained VEGF, bFGF, TGF-β1 and BMP2. P-ECM hydrogel maintained the viability of rDPSCs as compared to cells cultured under control conditions. P-ECM hydrogel triggered more organized tissues compared to BC, i-PRF and HA when used in REPs for necrotic mature teeth in dogs. Periapical inflammation was significantly less in HA and P-ECM groups compared to blood-derived scaffolds.

CONCLUSION

Bovine dental pulp-derived extracellular matrix (P-ECM) hydrogel scaffold retained its bioactive properties and demonstrated a promising potential in regenerative endodontic procedures compared to conventional blood-derived scaffolds.

Intradermal Treatment with a Hyaluronic Acid Complex Supplemented with Amino Acids and Antioxidant Vitamins Improves Cutaneous Hydration and Viscoelasticity in Healthy Subjects

Intradermal injection of bioactive compounds is used to reduce the effects of aging skin. The aim of this work is to study the response of facial injection of a hyaluronic acid complex supplemented with amino acids and antioxidant vitamins on skin rejuvenation. A total of 40 healthy adult subjects were recruited to whom this complex was injected into the facial skin, three consecutive times every two weeks. Together with assessing the degree of skin hydration, the level of skin microcirculation, wrinkles, skin color, and skin biomechanical parameters were evaluated. Using the GAIS scale, the degree of satisfaction of the participants was assessed. At 42 days (D42), there was an 11-12% increase in skin hydration and viscoelasticity, a 23% increase in skin density, a 27% increase in skin microcirculation, and a significant lightening and whitening of skin color, but without causing changes in skin wrinkles. A value between 1 and 3 on the GAIS scale was observed between 70 and 92% of the participants, and 87% of subjects found their skin more beautiful, 85% would recommend this treatment, and more than 50% found their face rejuvenated. In summary, the intradermal treatment tested suggests skin rejuvenation, with a good degree of safety.

Low, medium, and high molecular weight hyaluronic acid effects on human dental pulp stem cells in vitro

Hyaluronic acid (HA), an extracellular biopolymer found throughout the human body, holds promise as a biocompatible and biodegradable scaffold material. High molecular weight (HMW) HA degrades, generating low molecular weight (LMW) fragments with distinct properties. These fragments can influence the behaviour of cells, including human dental pulp stem cells (hDPSCs) incorporated into HA-containing hydrogels or scaffolds. Therefore, a comprehensive examination of the impact of a range of HA molecular weights on hDPSCs is essential before designing HA-based scaffolds for these cells. hDPSC lines were cultured with LMW HA (800 Da, 1600 Da, 15 kDa), medium molecular weight HA (237 kDa), or HMW HA (1500 kDa) over six passages. The various molecular weights had negligible effects on hDPSCs viability, morphology, adhesion, or relative telomere length. Furthermore, the expression of key surface stemness markers (CD29, CD44, CD73, CD90) remained unaltered. HA did not induce osteogenic, chondrogenic, or adipogenic differentiation. Moreover, the potential for chondrogenic and osteogenic differentiation was not adversely affected by LMW or HMW HA. Various molecular weights of HA seem safe, biocompatible and therefore suitable components for hDPSCs-containing scaffolds. These findings affirm that the hDPCSs will not be negatively affected by HA fragments resulting from scaffold degradation.

The Effect of Hydrogel Hyaluronic Acid on Dentine Sialophosphoprotein Expression of Human Dental Pulp Stem Cells

OBJECTIVE

Hyaluronic acid (HA) is glycosaminoglycan and one of important factors in extracellular matrix. In an inflamed pulp, when niche biology is conducive, the recruitment of human dental pulp stem cells (hDPSCs) will take place and differentiate into odontoblast like cell, creating reparative dentine and expressing dentine sialophosphoprotein (DSPP). Therefore, the purpose of this study was to analyze the potential of hydrogel HA in various concentration towards hDPSCs differentiation via DSPP expression at day 7 and 14.

METHODS

After hDPSCs incubation reaching 80% confluence, cells were then starved for 24 hours. Then, culture media were supplemented with osteogenic media. hDPSCs planted into 96 well plate and HA 10 μg/mL, 20 μg/mL, and 30 μg/mL were added. DSPP expression was analysed using elisa reader at day 7 and 14, qualitative result was analysed using alizarin red at day 21. Data was analysed using one-way ANOVA.

RESULTS

At day 7, there was a statistically significant different potential of HA conditioned media in various concentration (p<0.05) towards hDPSCs differentiation via expression of DSPP with HA 30 μg/mL being the most potential concentration to increase DSPP expression.

CONCLUSION

HA have the potential to increase odontoblast differentiation process via expression of DSPP, with HA 30 μg/mL being the optimum concentration for hDPSCs. (EEJ-2022-12-169).

Comprehensive review on biosynthesis of hyaluronic acid with different molecular weights and its biomedical applications

Hyaluronic acid (HA), an anionic and nonsulfated glycosaminoglycan, is the main structural component of various tissues and plays an important role in various biological processes. Given the promising properties of HA, such as high cellular compatibility, moisture retention, antiaging, proper interaction with cells, and CD44 targeting, HA can be widely used extensively in drug delivery, tissue engineering, wound healing, and cancer therapy. HA can obtain from animal tissues and microbial fermentation, but its applications depend on its molecular weight. Microbial fermentation is a common method for HA production on an industrial scale and S. zooepidemicus is the most frequently used strain in HA production. Culture conditions including pH, temperature, agitation rate, aeration speed, shear stress, dissolved oxygen, and bioreactor type significantly affect HA biosynthesis properties. In this review all the HA production methods and purification techniques to improve its physicochemical and biological properties for various biomedical applications are discussed in details. In addition, we showed that how HA molecular weight can significantly affect its properties and applications.

The effect of hyaluronic acid conditioned media on hDPSCs differentiation through CD44 and transforming growth factor-β1 expressions

Hyaluronic acid (HA) has the capability to influence dentin niche which is important in regenerative process. The CD44 as a specific receptor of HA was found to be related to dentin mineralization process. Meanwhile, transforming growth factor β1 (TGF-β1) has a vital role in the transition from proliferation into the differentiation of human dental pulp stem cell human dental pulp stem cells (hDPSCs) to become odontoblast cells and dentin mineralization. This study aims to analyzed HA's effect on dentin mineralization through CD44 and TGF-β1 expressions. Stem cells were cultured in four different supplemented conditioned media (control, +10 μg/mL, +20 μg/mL, and + 30 μg/mL of HA). Evaluation of CD44 expression was analyzed using flow cytometry and TGF-β1 was analyzed using enzyme-linked immunosorbent assay reader. Qualitative result using Alizarin red test after 21 days was done to confirm the formation of mineralization nodules. It was shown that HA expression of CD44 and TGF-β1 on hDPSCs were higher in AH groups compared to the control group and 30 μg/mL HA induced the highest TGF-β1 expression on hDPSCs. Alizarin red test also showed the highest mineralization nodules in the same group. Therefore, from this study, we found that supplemented 30 μg/mL of HA was proved in initiating hDPSCs differentiation process and promote dentin mineralization.

The Osteogenic Role of Biomaterials Combined with Human-Derived Dental Stem Cells in Bone Tissue Regeneration

The use of stem cells in regenerative medicine had great potential for clinical applications. However, cell delivery strategies have critical importance in stimulating the differentiation of stem cells and enhancing their potential to regenerate damaged tissues. Different strategies have been used to investigate the osteogenic potential of dental stem cells in conjunction with biomaterials through in vitro and in vivo studies. Osteogenesis has a broad implication in regenerative medicine, particularly for maxillofacial defects. This review summarizes some of the most recent developments in the field of tissue engineering using dental stem cells.

Structural Analysis and Classification of Low-Molecular-Weight Hyaluronic Acid by Near-Infrared Spectroscopy: A Comparison between Traditional Machine Learning and Deep Learning

Confusing low-molecular-weight hyaluronic acid (LMWHA) from acid degradation and enzymatic hydrolysis (named LMWHA-A and LMWHA-E, respectively) will lead to health hazards and commercial risks. The purpose of this work is to analyze the structural differences between LMWHA-A and LMWHA-E, and then achieve a fast and accurate classification based on near-infrared (NIR) spectroscopy and machine learning. First, we combined nuclear magnetic resonance (NMR), Fourier transform infrared (FTIR) spectroscopy, two-dimensional correlated NIR spectroscopy (2DCOS), and aquaphotomics to analyze the structural differences between LMWHA-A and LMWHA-E. Second, we compared the dimensionality reduction methods including principal component analysis (PCA), kernel PCA (KPCA), and t-distributed stochastic neighbor embedding (t-SNE). Finally, the differences in classification effect of traditional machine learning methods including partial least squares-discriminant analysis (PLS-DA), support vector classification (SVC), and random forest (RF) as well as deep learning methods including one-dimensional convolutional neural network (1D-CNN) and long short-term memory (LSTM) were compared. The results showed that genetic algorithm (GA)-SVC and RF were the best performers in traditional machine learning, but their highest accuracy in the test dataset was 90%, while the accuracy of 1D-CNN and LSTM models in the training dataset and test dataset classification was 100%. The results of this study show that compared with traditional machine learning, the deep learning models were better for the classification of LMWHA-A and LMWHA-E. Our research provides a new methodological reference for the rapid and accurate classification of biological macromolecules.

Characterization of a Stemness-Optimized Purification Method for Human Dental-Pulp Stem Cells: An Approach to Standardization

Human dental pulp stem cells (hDPSCs) are promising for oral/craniofacial regeneration, but their purification and characterization is not yet standardized. hDPSCs from three donors were purified by magnetic activated cell sorting (MACS)-assisted STRO-1-positive cell enrichment (+), colony derivation (c), or a combination of both (c/+). Immunophenotype, clonogenicity, stemness marker expression, senescence, and proliferation were analyzed. Multilineage differentiation was assessed by qPCR, immunohistochemistry, and extracellular matrix mineralization. To confirm the credibility of the results, repeated measures analysis and post hoc p-value adjustment were applied. All hDPSC fractions expressed STRO-1 and were similar for several surface markers, while their clonogenicity and expression of CD10/44/105/146, and 166 varied with the purification method. (+) cells proliferated significantly faster than (c/+), while (c) showed the highest increase in metabolic activity. Colony formation was most efficient in (+) cells, which also exhibited the lowest cellular senescence. All hDPSCs produced mineralized extracellular matrix. Regarding osteogenic induction, (c/+) revealed a significant increase in mRNA expression of COL5A1 and COL6A1, while osteogenic marker genes were detected at varying levels. (c/+) were the only population missing BDNF gene transcription increase during neurogenic induction. All hDPSCs were able to differentiate into chondrocytes. In summary, the three hDPSCs populations showed differences in phenotype, stemness, proliferation, and differentiation capacity. The data suggest that STRO-1-positive cell enrichment is the optimal choice for hDPSCs purification to maintain hDPSCs stemness. Furthermore, an (immuno) phenotypic characterization is the minimum requirement for quality control in hDPSCs studies.

Cells and material-based strategies for regenerative endodontics

The carious process leads to inflammation of pulp tissue. Current care options include root canal treatment or apexification. These procedures, however, result in the loss of tooth vitality, sensitivity, and healing. Pulp capping and dental pulp regeneration are continually evolving techniques to regenerate pulp tissue, avoiding necrosis and loss of vitality. Many studies have successfully employed stem/progenitor cell populations, revascularization approaches, scaffolds or material-based strategies for pulp regeneration. Here we outline advantages and disadvantages of different methods and techniques which are currently being used in the field of regenerative endodontics. We also summarize recent findings on efficacious peptide-based materials which target the dental niche.

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The applications of polysaccharides in dentistry

Polysaccharides are natural polymers widely present in animals, plants, and several microorganisms. Polysaccharides have remarkable properties, including easy extractions, degradability, and renewability, and have no apparent toxicity, making them ideal for biomedical applications. Moreover, polysaccharides are suitable for repairing oral tissue defects and treating oral diseases due to their excellent biocompatibility, biosafety, anti-inflammatory, and antibacterial properties. The oral cavity is a relatively complex environment vulnerable to numerous conditions, including soft tissue diseases, hard tissue disorders, and as well as soft and hard tissue diseases, all of which are complex to treat. In this article, we reviewed different structures of natural polysaccharides with high commercial values and their applications in treating various oral disease, such as drug delivery, tissue regeneration, material modification, and tissue repair.

Evaluation of the Hyaluronic Acid Versus the Injectable Platelet-Rich Fibrin in the Management of the Thin Gingival Phenotype: A Split-Mouth Randomized Controlled Clinical Trial

Background Several procedures have been used to enhance thin gingival phenotype and the majority of these procedures have been surgical. A new minimally invasive approach that involved multiple injections of platelet-rich fibrin (i-PRF) to enhance the thin gingival phenotype has been proposed. As the hyaluronic acid (HA) and the i-PRF share similar properties in terms of promoting periodontal regeneration, the present trial aimed to evaluate the effectiveness of multiple injections of the i-PRF in patients with thin gingival phenotypes in comparison with those of the HA in increasing the gingival thickness (GT) and the keratinized tissue width (KTW). Materials and methods Eighty-four sites from 14 systematically healthy patients who had thin gingival phenotypes (GT ≤1 mm) were included in this split-mouth randomized controlled trial. For each patient, each side of the anterior mandible was randomly allocated to one of the two materials (HA or i-PRF). In the HA group, the selected sites of the gingiva were injected with cross-linked HA using a 30-gauge microneedle. In the i-PRF group, the i-PRF was injected in the same manner. This procedure was repeated in both groups three times with intervals of 7 days. The GT, KTW, and periodontal indices: gingival index (GI), bleeding on probing (BOP), and probing depth (PD) were measured at baseline, 1 month, and 3 months following the initial injection. Results The GT increased significantly in both groups at the three assessment times (p<0.001). The KTW also showed a statistically significant increase in the intragroup comparisons in both groups (p<0.05). No statistically significant difference was observed between the two groups at the three assessment times for the GT and the KTW (p>0.05). The GI significantly decreased after 1 month and 3 months compared to the baseline values in both groups (p<0.05). The intergroup comparisons for the GI revealed no statistically significant differences at the three assessment times (p>0.05). As for the BOP and the PD, no statistically significant differences were found between the three assessment times (p>0.05) and between the two groups at each assessment time (p>0.05). Conclusion Multiple injections of the i-PRF and the HA in the thin gingival phenotype resulted in an increased GT and increased KTW, with no statistically significant differences between the two methods. Both minimally invasive techniques were more effective in improving the GT rather than the KTW.

Innovative Approach in the Cryogenic Freezing Medium for Mesenchymal Stem Cells

The physical stresses during cryopreservation affect stem cell survival and further proliferation. To minimize or prevent cryoinjury, cryoprotective agents (CPAs) are indispensable. Despite the widespread use of 10% dimethyl sulfoxide (DMSO), there are concerns about its potential adverse effects. To bypass those effects, combinations of CPAs have been investigated. This study aimed to verify whether high-molecular-hyaluronic acid (HMW-HA) serves as a cryoprotectant when preserving human mesenchymal stem cells (hMSCs) to reduce the DMSO concentration in the cryopreservation medium. We studied how 0.1% or 0.2% HMW-HA combined with reduced DMSO concentrations (from 10% to 5%, and 3%) affected total cell count, viability, immunophenotype, and differentiation potential post-cryopreservation. Immediately after cell revival, the highest total cell count was observed in 10% DMSO-stored hMSC. However, two weeks after cell cultivation an increased cell count was seen in the HMW-HA-stored groups along with a continued increase in hMSCs stored using 3% DMSO and 0.1% HMW-HA. The increased total cell count corresponded to elevated expression of stemness marker CD49f. The HA-supplemented cryomedium did not affect the differential potential of hMSC. Our results will participate in producing a ready-to-use product for cryopreservation of mesenchymal stem cells.

Tissue Regeneration and Physiological Functional Recovery in Dental and Craniofacial Fields

Dental and oral tissues maintain homeostasis through potential reparative or regenerative processes [...].

Effect of Hyaluronic Acid on the Differentiation of Mesenchymal Stem Cells into Mature Type II Pneumocytes

Hyaluronic acid (HA) is an essential component of the extracellular matrix (ECM) of the healthy lung, playing an important role in the structure of the alveolar surface stabilizing the surfactant proteins. Alveolar type II (ATII) cells are the fundamental element of the alveolus, specializing in surfactant production. ATII cells represent the main target of lung external lesion and a cornerstone in the repair process of pulmonary damage. In this context, knowledge of the factors influencing mesenchymal stem cell (MSC) differentiation in ATII cells is pivotal in fulfilling therapeutic strategies based on MSCs in lung regenerative medicine. To achieve this goal, the role of HA in promoting the differentiation of MSCs in mature Type II pneumocytes capable of secreting pulmonary surfactant was evaluated. Results demonstrated that HA, at a specific molecular weight can greatly increase the expression of lung surfactant protein, indicating the ability of HA to influence MSC differentiation in ATII cells.