Mussel-Inspired Polydopamine Composite Mesoporous Bioactive Glass Nanoparticles: An Exploration of Potential Metal-Ion Loading Platform and In Vitro Bioactivity

Evaluation of enamel remineralization potential and anticariogenic efficacy of polydopamine coated biogenic amorphous calcium phosphate

OBJECTIVES

The aim of this study was to comparatively evaluate the enamel remineralization potential and antibacterial efficacy of polydopamine coated chicken eggshell derived amorphous calcium phosphate (PDA -EACP) and casein phosphopeptide-amorphous calcium phosphate (CPP-ACP).

MATERIALS AND METHODS

EACP was synthesized from chicken eggshells, functionalized with PDA, and then characterized using high-resolution scanning electron microscopy with energy-dispersive X-ray spectroscopy (HRSEM-EDX), Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD). 120 enamel slabs were demineralized and randomly divided into 5 groups for the following therapeutic treatments: Group I- Control (no treatment); Group II - CPP-ACP; Group III- EACP; Group IV- PDA; Group V- PDA-EACP and subjected to a 28-day pH cycling regimen. The remineralization effects were assessed by measuring changes in Vickers Microhardness (VMH), analyzing surface morphology using SEM and performing elemental and chemical analysis through EDX and XRD. Antibacterial efficacy was evaluated using agar diffusion, direct contact, and biofilm inhibition assays using fluorescent staining method against Streptococcus mutans.

RESULTS

Post-demineralization, VMH values dropped from 340 to 350 VHN to ~ 200-214 VHN. PDA-EACP showed the highest remineralization (330.4 ± 12.2 VHN), significantly greater than EACP (295.6 ± 10.4 VHN) and CPP-ACP (265.3 ± 9.8 VHN) (p < 0.001). EDX analysis showed Ca/P ratio increased to 2.31 ± 0.34 (EACP) and 1.69 ± 0.06 (PDA-EACP). XRD confirmed superior hydroxyapatite crystallization in PDA-EACP. PDA-EACP exhibited the largest inhibition zone (15.6 ± 1.3 mm) and highest biofilm reduction (72.6% bacterial death at 1:1 dilution).

CONCLUSION

PDA-EACP enhances enamel remineralization and antibacterial activity more than CPP-ACP.

CLINICAL RELEVANCE

PDA-EACP provides a biomimetic, cost-effective, and biocompatible alternative to synthetic remineralizing agents to treat early enamel lesions. Its strong adhesion potential, mineralization and antimicrobial properties could improve clinical outcomes in managing and preventing incipient carious lesions.

3D-printed gallium-infused scaffolds for osteolysis intervention and bone regeneration

Exacerbation of osteolysis in osteoporotic bone defects presents a significant challenge for implant-based treatments. This underscores the urgent need to develop implants that actively mitigate osteolysis while simultaneously promoting bone regeneration. In this study, the osteogenic potential of mesoporous bioactive glass (MBG) and β-tricalcium phosphate (β-TCP) was combined with the anti-bone resorption property of Ga doping. Ga-MBG was synthesized using a self-transformation method and subsequently incorporated into β-TCP at concentrations of 5 wt%, 10 wt% and 15 wt%. Scaffolds were prepared using extrusion-based 3D printing. The cytocompatibility of the composite scaffolds and their regulatory effects on the differentiation of osteoblasts and osteoclasts were systematically examined. In addition, the molecular mechanisms underlying bone regeneration and osteolysis regulation in osteoblasts were explored. Subsequently, cranial defects were repaired in a rat model of osteoporosis to assess the therapeutic efficacy and biological safety of the optimal concentration of the Ga-MBG/TCP composite scaffold. These findings indicated that the 10 wt% Ga-MBG/TCP composite scaffold exhibited excellent biocompatibility, enhanced new bone formation, and effectively mitigated osteolysis. These results provide a foundation for further investigation into the optimal concentration of Ga-MBG implants and highlight their potential application in future therapies for osteoporotic bone defects.

Membrane-camouflaged biomimetic nanoplatform with arsenic complex for synergistic reinforcement of liver cancer therapy

Aim: Arsenic has excellent anti-advanced liver cancer effects through a variety of pathways, but its severe systemic toxicity forces the need for a safe and effective delivery strategy.Methods: Based on the chelating metal ion properties of polydopamine (PDA), arsenic was immobilized on an organic carrier, and a M1-like macrophage cell membrane (MM)-camouflaged manganese-arsenic complex mesoporous polydopamine (MnAsOx@MP@M) nanoplatform was successfully constructed. MnAsOx@MP@M was evaluated at the cellular level for tumor inhibition and tumor localization, and in vivo for its anti-liver cancer effect in a Hepa1-6 tumor-bearing mouse model.Results: The nanoplatform targeted the tumor site through the natural homing property of MM, completely degraded and released drugs to kill tumor cells in an acidic environment, while playing an immunomodulatory role in promoting tumor-associated macrophages (TAMs) repolarization.Conclusion: MnAsOx@MP@M has synergistically enhanced the targeted therapeutics against liver cancer via nanotechnology and immunotherapy, and it is expected to become a safe and multifunctional treatment platform in clinical oncology.

A novel mussel-inspired desensitizer based on radial mesoporous bioactive nanoglass for the treatment of dentin exposure: An in vitro study

OBJECTIVES

The dentin exposure always leads to dentin hypersensitivity and the acid-resistant/abrasion-resistant stability of current therapeutic approaches remain unsatisfatory. Inspired by the excellent self-polymerization/adherence activity of mussels and the superior mineralization ability of bioactive glass, a novel radial mesoporous bioactive nanoglass coated with polydopamine (RMBG@PDA) was developed for prevention and management of dentin hypersensitivity.

METHODS

Radial mesoporous bioactive nanoglass (RMBG) was synthesized by the sol-gel process combined with the cetylpyridine bromide template self-assembly technique. RMBG@PDA was synthesized by a self-polymerization process involving dopamine and RMBG in an alkaline environment. Then, the nanoscale morphology, chemical structure, crystalline phase and Zeta potential of RMBG and RMBG@PDA were characterized. Subsequently, the ion release ability, bioactivity, and cytotoxicity of RMBG and RMBG@PDA in vitro were investigated. Moreover, an in vitro experimental model of dentin hypersensitivity was constructed to evaluate the effectiveness of RMBG@PDA on dentinal tubule occlusion, including resistances against acid and abrasion. Finally, the Young's modulus and nanohardness of acid-etched dentin were also detected after RMBG@PDA treatment.

RESULTS

RMBG@PDA showed a typical nanoscale morphology and noncrystalline structure. The use of RMBG@PDA on the dentin surface could effectively occlude dentinal tubules, reduce dentin permeability and achieve excellent acid- and abrasion-resistant stability. Furthermore, RMBG@PDA with excellent cytocompatibility held the capability to recover the Young's modulus and nanohardness of acid-etched dentin.

CONCLUSION

The application of RMBG@PDA with superior dentin tubule occlusion ability and acid/abrasion-resistant stability can provide a therapeutic strategy for the prevention and the management of dentin hypersensitivity.