Bifunctional naringenin-laden gelatin methacryloyl scaffolds with osteogenic and anti-inflammatory properties.

OBJECTIVE: To fabricate and characterize an innovative gelatin methacryloyl/GelMA electrospun scaffold containing the citrus flavonoid naringenin/NA with osteogenic and anti-inflammatory properties. METHODS: GelMA scaffolds (15 % w/v) containing 0/Control, 5, 10, or 20 % of NA w/w were obtained via electrospinning. The chemical composition, fiber morphology/diameter, swelling/degradation profile, and NA release were investigated. Cytotoxicity, cell proliferation, adhesion and spreading, total protein/TP production, alkaline phosphatase/ALP activity, osteogenic genes expression (OCN, OPN, RUNX2), and mineralized nodules deposition/MND with human alveolar bone-derived mesenchymal stem cells (aBMSCs) seeded on the scaffolds were assessed. Moreover, aBMSCs seeded on the scaffolds and stimulated with tumor necrosis factor-alpha/TNF-α were submitted to collagen, nitric oxide/NO, interleukin/IL-1α, and IL-6 production assessment. Data were analyzed using ANOVA and t-student/post-hoc tests (α = 5 %). RESULTS: NA-laden scaffolds presented increased fiber diameter, lower swelling capacity, and faster degradation profile over 28 days (p < 0.05). NA release was detected over time. Cell adhesion and spreading, and TP production were similar between GelMA and GelMA+NA5 % scaffolds, while cell proliferation, ALP activity, OCN/OPN/RUNX2 gene expression, and MND were higher for GelMA+NA5 % scaffolds (p < 0.05). Cells seeded on control scaffolds and TNF-α-stimulated presented higher levels of NO, IL-1α/IL-6, and lower levels of collagen (p < 0.05). In contrast, cells seeded on GelMA+NA5 % scaffolds showed downregulation of inflammatory markers and higher collagen synthesis (p < 0.05). SIGNIFICANCE: GelMA+NA5 % scaffold was cytocompatible, stimulated aBMSCs proliferation and differentiation, and downregulated inflammatory mediators' synthesis, suggesting its therapeutic effect as a multi-target bifunctional scaffold with osteogenic and anti-inflammatory properties for bone tissue engineering.

GelMA/TCP nanocomposite scaffold for vital pulp therapy.

Pulp capping is a necessary procedure for preserving the vitality and health of the dental pulp, playing a crucial role in preventing the need for root canal treatment or tooth extraction. Here, we developed an electrospun gelatin methacryloyl (GelMA) fibrous scaffold incorporating beta-tricalcium phosphate (TCP) particles for pulp capping. A comprehensive morphological, physical-chemical, and mechanical characterization of the engineered fibrous scaffolds was performed. In vitro bioactivity, cell compatibility, and odontogenic differentiation potential of the scaffolds in dental pulp stem cells (DPSCs) were also evaluated. A pre-clinical in vivo model was used to determine the therapeutic role of the GelMA/TCP scaffolds in promoting hard tissue formation. Morphological, chemical, and thermal analyses confirmed effective TCP incorporation in the GelMA nanofibers. The GelMA+20%TCP nanofibrous scaffold exhibited bead-free morphology and suitable mechanical and degradation properties. In vitro, GelMA+20%TCP scaffolds supported apatite-like formation, improved cell spreading, and increased deposition of mineralization nodules. Gene expression analysis revealed upregulation of ALPL, RUNX2, COL1A1, and DMP1 in the presence of TCP-laden scaffolds. In vivo, analyses showed mild inflammatory reaction upon scaffolds' contact while supporting mineralized tissue formation. Although the levels of Nestin and DMP1 proteins did not exceed those associated with the clinical reference treatment (i.e., mineral trioxide aggregate), the GelMA+20%TCP scaffold exhibited comparable levels, thus suggesting the emergence of differentiated odontoblast-like cells capable of dentin matrix secretion. Our innovative GelMA/TCP scaffold represents a simplified and efficient alternative to conventional pulp-capping biomaterials. STATEMENT OF SIGNIFICANCE: Vital pulp therapy (VPT) aims to preserve dental pulp vitality and avoid root canal treatment. Biomaterials that bolster mineralized tissue regeneration with ease of use are still lacking. We successfully engineered gelatin methacryloyl (GelMA) electrospun scaffolds incorporated with beta-tricalcium phosphate (TCP) for VPT. Notably, electrospun GelMA-based scaffolds containing 20% (w/v) of TCP exhibited favorable mechanical properties and degradation, cytocompatibility, and mineralization potential indicated by apatite-like structures in vitro and mineralized tissue deposition in vivo, although not surpassing those associated with the standard of care. Collectively, our innovative GelMA/TCP scaffold represents a simplified alternative to conventional pulp capping materials such as MTA and Biodentine™ since it is a ready-to-use biomaterial, requires no setting time, and is therapeutically effective.

Calcium Trimetaphosphate-Loaded Electrospun Poly(Ester Urea) Nanofibers for Periodontal Tissue Engineering.

The objective of this research was to create and appraise biodegradable polymer-based nanofibers containing distinct concentrations of calcium trimetaphosphate (Ca-TMP) for periodontal tissue engineering. Poly(ester urea) (PEU) (5% w/v) solutions containing Ca-TMP (15%, 30%, 45% w/w) were electrospun into fibrous scaffolds. The fibers were evaluated using SEM, EDS, TGA, FTIR, XRD, and mechanical tests. Degradation rate, swelling ratio, and calcium release were also evaluated. Cell/Ca-TMP and cell/scaffold interaction were assessed using stem cells from human exfoliated deciduous teeth (SHEDs) for cell viability, adhesion, and alkaline phosphatase (ALP) activity. Analysis of variance (ANOVA) and post-hoc tests were used (α = 0.05). The PEU and PEU/Ca-TMP-based membranes presented fiber diameters at 469 nm and 414-672 nm, respectively. Chemical characterization attested to the Ca-TMP incorporation into the fibers. Adding Ca-TMP led to higher degradation stability and lower dimensional variation than the pure PEU fibers; however, similar mechanical characteristics were observed. Minimal calcium was released after 21 days of incubation in a lipase-enriched solution. Ca-TMP extracts enhanced cell viability and ALP activity, although no differences were found between the scaffold groups. Overall, Ca-TMP was effectively incorporated into the PEU fibers without compromising the morphological properties but did not promote significant cell function.

Nanoscale ß-TCP-Laden GelMA/PCL Composite Membrane for Guided Bone Regeneration.

Major advances in the field of periodontal tissue engineering have favored the fabrication of biodegradable membranes with tunable physical and biological properties for guided bone regeneration (GBR). Herein, we engineered innovative nanoscale beta-tricalcium phosphate (ß-TCP)-laden gelatin methacryloyl/polycaprolactone (GelMA/PCL-TCP) photocrosslinkable composite fibrous membranes via electrospinning. Chemo-morphological findings showed that the composite microfibers had a uniform porous network and ß-TCP particles successfully integrated within the fibers. Compared with pure PCL and GelMA/PCL, GelMA/PCL-TCP membranes led to increased cell attachment, proliferation, mineralization, and osteogenic gene expression in alveolar bone-derived mesenchymal stem cells (aBMSCs). Moreover, our GelMA/PCL-TCP membrane was able to promote robust bone regeneration in rat calvarial critical-size defects, showing remarkable osteogenesis compared to PCL and GelMA/PCL groups. Altogether, the GelMA/PCL-TCP composite fibrous membrane promoted osteogenic differentiation of aBMSCs in vitro and pronounced bone formation in vivo. Our data confirmed that the electrospun GelMA/PCL-TCP composite has a strong potential as a promising membrane for guided bone regeneration.

Multifunctional and biodegradable methacrylated gelatin/Aloe vera nanofibers for endodontic disinfection and immunomodulation.

Currently employed approaches and materials used for vital pulp therapies (VPTs) and regenerative endodontic procedures (REPs) lack the efficacy to predictably achieve successful outcomes due to their inability to achieve adequate disinfection and/or lack of desired immune modulatory effects. Natural polymers and medicinal herbs are biocompatible, biodegradable, and present several therapeutic benefits and immune-modulatory properties; thus, standing out as a clinically viable approach capable of establishing a conducive environment devoid of bacteria and inflammation to support continued root development, dentinal bridge formation, and dental pulp tissue regeneration. However, the low stability and poor mechanical properties of the natural compounds have limited their application as potential biomaterials for endodontic procedures. In this study, Aloe vera (AV), as a natural antimicrobial and anti-inflammatory agent, was incorporated into photocrosslinkable Gelatin methacrylate (GelMA) nanofibers with the purpose of developing a highly biocompatible biomaterial capable of eradicating endodontic infection and modulating inflammation. Stable GelMA/AV nanofibers with optimal properties were obtained at the ratio of (70:30) by electrospinning. In addition to the pronounced antibacterial effect against Enterococcus faecalis, the GelMA/AV (70:30) nanofibers also exhibited a sustained antibacterial activity over 14 days and significant biofilm reduction with minimal cytotoxicity, as well as anti-inflammatory properties and immunomodulatory effects favoring healing. Our results indicate that the novel GelMA/AV (70:30) nanofibers hold great potential as a biomaterial strategy for endodontic infection eradication and enhanced healing.

Electrospun Azithromycin-Laden Gelatin Methacryloyl Fibers for Endodontic Infection Control.

This study was aimed at engineering photocrosslinkable azithromycin (AZ)-laden gelatin methacryloyl fibers via electrospinning to serve as a localized and biodegradable drug delivery system for endodontic infection control. AZ at three distinct amounts was mixed with solubilized gelatin methacryloyl and the photoinitiator to obtain the following fibers: GelMA+5%AZ, GelMA+10%AZ, and GelMA+15%AZ. Fiber morphology, diameter, AZ incorporation, mechanical properties, degradation profile, and antimicrobial action against Aggregatibacter actinomycetemcomitans and Actinomyces naeslundii were also studied. In vitro compatibility with human-derived dental pulp stem cells and inflammatory response in vivo using a subcutaneous rat model were also determined. A bead-free fibrous microstructure with interconnected pores was observed for all groups. GelMA and GelMA+10%AZ had the highest fiber diameter means. The tensile strength of the GelMA-based fibers was reduced upon AZ addition. A similar pattern was observed for the degradation profile in vitro. GelMA+15%AZ fibers led to the highest bacterial inhibition. The presence of AZ, regardless of the concentration, did not pose significant toxicity. In vivo findings indicated higher blood vessel formation, mild inflammation, and mature and thick well-oriented collagen fibers interweaving with the engineered fibers. Altogether, AZ-laden photocrosslinkable GelMA fibers had adequate mechanical and degradation properties, with 15%AZ displaying significant antimicrobial activity without compromising biocompatibility.