Encapsulation of a novel peptide derived from histatin-1 in liposomes against initial enamel caries in vitro and in vivo.

OBJECTIVES: Biomimetic mineralization mediated by proteins and peptides is a promising strategy for enamel repair, and its specific application model needs more research. In this work, we exploited a liposomal delivery system for a novel peptide (DK5) derived from histatin-1 (DK5-Lips) as a new biomimetic mineralization strategy against initial enamel caries. MATERIALS AND METHODS: The DK5-Lips was prepared using calcium acetate gradient method and then the in vitro release, salivary stability, and cytotoxicity were studied. Initial enamel caries was created in bovine enamel blocks and subjected to pH-cycling model treated with DK5-Lips. Surface microhardness testing, polarized light microscopy (PLM), and transverse microradiography (TMR) were analyzed. Then the biocompatibility of DK5-Lips was evaluated in the caries model of Sprague-Dawley rats, and the anti-caries effect was assessed using Micro-CT analysis, Keyes scores, and PLM in vivo. RESULTS: DK5-Lips provided a mean particle size of (97.63 ± 4.94)nm and encapsulation efficiency of (61.46 ± 1.44)%, exhibiting a sustained release profile, excellent stability in saliva, and no significant toxicity on human gingival fibroblasts (HGFs). The DK5-Lips group had higher surface microhardness recovery, shallower caries depth, and less mineral loss in bovine enamel. Animal experiments showed higher volume and density values of residual molar enamel, lower Keyes score, and shallower lesion depth of the DK5-Lips group with good biocompatibility. CONCLUSION: As a safe and effective application model, DK5-Lips could significantly promote the remineralization of initial enamel caries both in vitro and in vivo. CLINICAL RELEVANCE: The potential of liposome utilization as vehicle for oral delivery of functional peptides may provide a new way for enamel restoration.

TVH-19, a synthetic peptide, induces mineralization of dental pulp cells in vitro and formation of tertiary dentin in vivo.

Functional peptides derived from the active domains of odontogenesis-related proteins have been reported to promote dental hard tissue regeneration. The purpose of this study was to evaluate the effects of an artificially synthesized peptide, TVH-19, on odontoblast differentiation and tertiary dentin formation in indirect pulp capping (IPC) using in vitro and in vivo experiments. TVH-19 did not exhibit any effect on the proliferation of human dental pulp cells (hDPCs) but significantly promoted cell migration, compared with the control (p < 0.05). TVH-19-treated hDPCs showed significantly higher alkaline phosphatase (ALP) activity and stronger alizarin red staining (ARS) reactivity than the control group (p < 0.05). TVH-19 also upregulated the mRNA and protein expression levels of odontogenic genes. After generating IPC in rats, the samples of teeth were studied using micro-computed tomography (Micro-CT), hematoxylin & eosin (HE) staining, and immunohistochemical staining to investigate the functions of TVH-19. The in vivo results showed that TVH-19 induced the formation of tertiary dentin, and reduced inflammation and apoptosis, as evident from the downregulated expression of interleukin 6 (IL-6) and cleaved-Caspase-3 (CL-CASP3). Overall, the results of our study suggest that TVH-19 induces differentiation of hDPCs, promotes tertiary dentin formation, relieves inflammation, and reduces apoptosis, indicating the potential applications of TVH-19 in IPC.

Electrospun nanofibers applications in caries lesions: prevention, treatment and regeneration.

Dental caries is a multifactorial disease primarily mediated by biofilm formation, resulting in a net loss of mineral content and degradation of organic matrix in dental hard tissues. Caries lesions of varying depths can result in demineralization of the superficial enamel, the formation of deep cavities extending into the dentin, and even pulp infection. Electrospun nanofibers (ESNs) exhibit an expansive specific surface area and a porous structure, closely mimicking the unique architecture of the natural extracellular matrix (ECM). This unique topography caters to the transport of small molecules and facilitates localized therapeutic drug delivery, offering great potential in regulating cell behavior, and thereby attracting interest in ESNs' applications in the treatment of caries lesions and the reconditioning of the affected dental tissues. Thus, this review aims to consolidate the recent developments in ESNs' applications for caries lesions. This review begins with an introduction to the electrospinning technique and provides a comprehensive overview of the biological properties and modification methods of ESNs, followed by an introduction outlining the basic pathological processes, classification and treatment requirements of caries lesions. Finally, the review offers a detailed examination of the research progress on the ESNs' application in caries lesions and concludes by addressing the limitations.

[Regulation of chondrosarcoma cell growth using synthesized hydrogels with different electric charges].

To develop standard in vitro chondrosarcoma models, we synthesized three hydrogels (i. e., PDMAAm, PNaAMPS and PMETAC) and investigated the influence of Young's modulus, swelling ratio and electric charges on the behavior of chondrosarcoma cells seeded on the hydrogels, including morphology, adhesion and aggregation. Results showed that the morphology of chondrosarcoma cells at 6h was dependent on the charges of hydrogels; cells present spindle-shaped and round-shaped morphology on negative charged and neutral hydrogel, respectively, while no cells spreaded on positive charged hydrogel. Chondrosarcoma cells formed aggregates on neutral PDMAAm after further culture. The hydrogels can be synthesized easily and has the characteristics of ease at use with defined components, which holds great potential for developing standard chondrosarcoma models in vitro.

Saliva biomarkers in oral disease.

Saliva is a versatile biofluid that contains a wide variety of biomarkers reflecting both physiologic and pathophysiologic states. Saliva collection is noninvasive and highly applicable for tests requiring serial sampling. Furthermore, advances in test accuracy, sensitivity and precision for saliva has improved diagnostic performance as well as the identification of novel markers especially in oral disease processes. These include dental caries, periodontitis, oral squamous cell carcinoma (OSCC) and Sjögren's syndrome (SS). Numerous growth factors, enzymes, interleukins and cytokines have been identified and are the subject of much research investigation. This review highlights current procedures for successful determination of saliva biomarkers including preanalytical factors associated with sampling, storage and pretreatment as well as subsequent analysis. Moreover, it provides an overview of the diagnostic applications of these salivary biomarkers in common oral diseases.

Effects of caffeic acid phenethyl ester against multi-species cariogenic biofilms.

Dental caries is a biofilm-related disease, widely perceived to be caused by oral ecological imbalance when cariogenic/aciduric bacteria obtain an ecological advantage. Compared with planktonic bacteria, dental plaques are difficult to remove under extracellular polymeric substance protection. In this study, the effect of caffeic acid phenethyl ester (CAPE) on a preformed cariogenic multi-species biofilm was evaluated, which was comprised of cariogenic bacteria (Streptococcus mutans), commensal bacteria (Streptococcus gordonii), and a pioneer colonizer (Actinomyces naeslundii). Our result revealed that treatment with 0.08 mg/mL CAPE reduced live S. mutans in the preformed multi-species biofilm while not significantly changing the quantification of live S. gordonii. CAPE significantly reduced the production of lactic acid, extracellular polysaccharide, and extracellular DNA and made the biofilm looser. Moreover, CAPE could promote the H2O2 production of S. gordonii and inhibit the expression of SMU.150 encoding mutacin to modulate the interaction among species in biofilms. Overall, our results suggested that CAPE could inhibit the cariogenic properties and change the microbial composition of the multi-species biofilms, indicating its application potential in dental caries prevention and management.

Increasing Cellular Uptake and Permeation of Curcumin Using a Novel Polymer-Surfactant Formulation.

Several therapeutically active molecules are poorly water-soluble, thereby creating a challenge for pharmaceutical scientists to develop an active solution for their oral drug delivery. This study aimed to investigate the potential for novel polymer-surfactant-based formulations (designated A and B) to improve the solubility and permeability of curcumin. A solubility study and characterization studies (FTIR, DSC and XRD) were conducted for the various formulations. The cytotoxicity of formulations and commercial comparators was tested via MTT and LDH assays, and their permeability by in vitro drug transport and cellular drug uptake was established using the Caco-2 cell model. The apparent permeability coefficients (Papp) are considered a good indicator of drug permeation. However, it can be argued that the magnitude of Papp, when used to reflect the permeability of the cells to the drug, can be influenced by the initial drug concentration (C0) in the donor chamber. Therefore, Papp (suspension) and Papp (solution) were calculated based on the different values of C0. It was clear that Papp (solution) can more accurately reflect drug permeation than Papp (suspension). Formulation A, containing Soluplus® and vitamin E TPGs, significantly increased the permeation and cellular uptake of curcumin compared to other samples, which is believed to be related to the increased aqueous solubility of the drug in this formulation.

A novel amelogenesis-inspired hydrogel composite for the remineralization of enamel non-cavitated lesions.

Enamel non-cavitated lesions (NCLs) are subsurface enamel porosity from carious demineralization. The developed enamel cannot repair itself once NCLs occurs. The regeneration of mineral crystals in a biomimetic environment is an effective way to repair enamel subsurface defects. Previously, an amelogenin-derived peptide named QP5 was proven to repair demineralized enamel. In this work, inspired by amelogenesis, a novel biomimetic hydrogel composite containing the QP5 peptide and bioactive glass (BG) was designed, in which QP5 could promote enamel remineralization by guiding the calcium and phosphorus ions provided by BG. Also, BG could adjust the mineralization micro-environment to alkalinity, simulating the pH regulation of ameloblasts during enamel maturity. The BQ hydrogel composite showed biosafety and possessed capacity for enamel binding, ion release and pH buffering. Enamel NCLs treated with the BQ hydrogel composite showed a higher reduction in lesion depth and mineral loss both in vitro and in vivo. Moreover, compared to the hydrogels containing only BG or QP5, groups treated with the BQ hydrogel composite attained more surface microhardness recovery and color recovery, exhibiting resistance to erosion and abrasion of the remineralization layer. We envision that the BQ hydrogel composite can provide a biomimetic micro-environment to favor enamel remineralization, thus reducing the lesion depth and increasing the mineral content as a promising biomimetic material for enamel NCLs.

Evaluating the potential of an amelogenin-derived peptide in tertiary dentin formation.

Several novel biomaterials have been developed for dental pulp capping by inducing tertiary dentin formation. The aim of this study was to evaluate the effect of QP5, an amelogenin-based peptide, on the mineralization of dental pulp cells (DPCs) in vitro and in vivo. The cell viability of human DPCs (hDPCs) after treatment with QP5 was determined using the Cell Counting Kit-8 (CCK-8). Migration of hDPCs was assessed using scratch assays, and the pro-mineralization effect was determined using alkaline phosphatase (ALP) staining, alizarin red staining and the expression of mineralization-related genes and proteins. The results showed that QP5 had little effect on the cell viability, and significantly enhanced the migration capability of hDPCs. QP5 promoted the formation of mineralized nodules, and upregulated the activity of ALP, the expression of mRNA and proteins of mineralization-related genes. A pulp capping model in rats was generated to investigate the biological effect of QP5. The results of micro-computed tomography and haematoxylin and eosin staining indicated that the formation of tertiary dentin in QP5-capping groups was more prominent than that in the negative control group. These results indicated the potential of QP5 as a pulp therapy agent.

The Amelogenin-Derived Peptide TVH-19 Promotes Dentinal Tubule Occlusion and Mineralization.

In this study, the amelogenin-derived peptide, TVH-19, which has been confirmed to promote mineralization, was evaluated to derive its potential to induce dentinal tubule occlusion. The binding capability of fluorescein isothiocyanate (FITC)-labeled TVH-19 to the demineralized dentin surface was analyzed by confocal laser scanning microscopy (CLSM). Additionally, the sealing function of the peptide was studied through the remineralization of demineralized dentin in vitro. The adsorption results showed that TVH-19 could bind to the hydroxyapatite and demineralized dentin surfaces, especially to periodontal dentin. Scanning electron microscopy analysis further revealed that TVH-19 created mineral precipitates. The plugging rate in the TVH-19 group was higher than that in the PBS group. Moreover, energy-dispersive X-ray spectroscopy (EDX) results indicated that the calcium/phosphorus (Ca/P) ratio of the new minerals induced by TVH-19 was close to that of the hydroxyapatite. Attenuated total internal reflection-Fourier transform infrared (ATR-FTIR) spectrometry and X-ray diffraction (XRD) results indicated that the hydroxyapatite crystals formed via remineralization elongated the axial growth and closely resembled the natural dentin components. These findings indicate that TVH-19 can effectively promote dentin sealing by binding to the periodontal dentin, promoting mineral deposition, and reducing the space between the dentin tubules.

A novel theranostic nanoplatform for imaging-guided chemo-photothermal therapy in oral squamous cell carcinoma.

Oral squamous cell carcinoma (OSCC) is highly malignant and invasive, and current treatments are limited due to serious side effects and unsatisfactory outcomes. Here, we reported the terbium ion-doped hydroxyapatite (HATb) nanoparticle as a luminescent probe to encapsulate both the near-infrared (NIR) photothermal agent polydopamine (PDA) and anticancer doxorubicin (DOX) for imaging-guided chemo-photothermal therapy. The morphology, crystal structure, fluorescence, and composition of HATb-PDA-DOX were characterized. HATb-PDA showed a high DOX loading capacity. A theranostic nanoplatform showed pH/NIR responsive release properties and better antitumor outcomes in OSCC cells than monomodal chemotherapy or photothermal therapy, while keeping side effects at a minimum. Also, the luminescence signal was confirmed to be tracked and the increase of the red/green (R/G) ratio caused by the DOX release could be used to monitor the DOX release content. Furthermore, HATb-PDA-DOX plus NIR treatment synergistically promoted in vitro cell death through the overproduction of reactive oxygen species (ROS), cell cycle arrest, and increased cell apoptosis. Overall, this work presents an innovative strategy in designing a multifunctional nano-system for imaging-guided cancer treatment.