Effects of Novel Nanoparticulate Bioceramic Endodontic Material on Human Dental Pulp Stem Cells In Vitro

Objectives: This study aimed to investigate the in vitro effects of root canal filling and repair paste (nRoot BP) on human dental pulp stem cells (hDPSCs). Methods: The effects of nRoot BP and iRoot BP Plus on the adhesion, proliferation, migration, and differentiation of hDPSCs were examined in vitro for 72 hours. The adhesion of cells was observed using immunofluorescence rhodamine ghost pen cyclic peptide staining and scanning electron microscopy (SEM). Cell density and changes in migration area were measured under a fluorescence inverted microscope. Fluorescent quantitative PCR was performed to detect genes related to odontogenesis and osteogenesis. Results: Cells adhering to the surfaces of nRoot BP and iRoot BP Plus exhibited similar irregular polygonal morphologies, with cells extending irregular pseudopods to adhere to the materials. CCK-8 results indicated that the density of living cells for nRoot BP and iRoot BP Plus was lower than that of the blank control group at 3 and 5 days of culture. There was no significant difference in cell migration between the groups (P > .05). The migration ability of iRoot BP Plus and nRoot BP was similar to that of the control group. Both nRoot BP and iRoot BP Plus increased the expression of the RUNX2 gene, but there was no significant difference between the groups (P .05). Conclusions: nRoot BP exhibited a slight inhibition of hDPSC proliferation but did not affect the adhesion and migration of hDPSCs. The impact of nRoot BP on the osteogenic and odontogenic differentiation of hDPSCs was similar to that of iRoot BP Plus

Preparation of PDA-GO/CS composite scaffold and its effects on the biological properties of human dental pulp stem cells

Abstract Reduced graphene oxide (rGO) is an graphene oxide (GO) derivative of graphene, which has a large specific surface area and exhibited satisfactory physicochemical characteristics. In this experiment, GO was reduced by PDA to generate PDA-GO complex, and then PDA-GO was combined with Chitosan (CS) to synthesize PDA-GO/CS composite scaffold. PDA-GO was added to CS to improve the degradation rate of CS, and it was hoped that PDA-GO/CS composite scaffolds could be used in bone tissue engineering. Physicochemical and antimicrobial properties of the different composite scaffolds were examined to find the optimal mass fraction. Besides, we examined the scaffold’s biocompatibility by Phalloidin staining and Live and Dead fluorescent staining. Finally, we applied ALP staining, RT-qPCR, and Alizarin red S staining to detect the effect of PDA-GO/CS on the osteogenic differentiation of human dental pulp stem cells (hDPSCs). The results showed that PDA-GO composite was successfully prepared and PDA-GO/CS composite scaffold was synthesized by combining PDA-GO with CS. Among them, 0.3%PDA-GO/CS scaffolds improves the antibacterial activity and hydrophilicity of CS, while reducing the degradation rate. In vitro, PDA-GO/CS has superior biocompatibility and enhances the early proliferation, migration and osteogenic differentiation of hDPSCs. In conclusion, PDA-GO/CS is a new scaffold materialsuitable for cell culture and has promising application prospect as scaffold for bone tissue engineering

Inhibition of SARS-CoV-2 Replication by Self-Assembled siRNA Nanoparticles Targeting Multiple Highly Conserved Viral Sequences

Coronavirus infectious disease 2019 (COVID-19), caused by severe acute respiratory virus type 2 (SARS-CoV-2), has caused a global public health crisis. As an RNA virus, the high gene mutability of SARS-CoV-2 poses significant challenges to the development of broad-spectrum vaccines and antiviral therapeutics. There remains a lack of specific therapeutics directly targeting SARS-CoV-2. With the ability to efficiently inhibit the expression of target genes in a sequence-specific way, small interfering RNA (siRNA) therapy has exhibited significant potential in antiviral and other disease treatments. In this work, we presented a highly effective self-assembled siRNA nanoparticle targeting multiple highly conserved regions of SARS-CoV-2. The siRNA sequences targeting viral conserved regions were first screened and evaluated by their thermodynamic features, off-target effects, and secondary structure toxicities. RNA motifs including siRNA sequences were then designed and self-assembled into siRNA nanoparticles. These siRNA nanoparticles demonstrated remarkable uniformity and stability and efficiently entered cells directly through cellular endocytic pathways. Moreover, these nanoparticles effectively inhibited the replication of SARS-CoV-2, exhibiting a superior inhibitory effect compared to free siRNA. These results demonstrated that these self-assembled siRNA nanoparticles targeting highly conserved regions of SARS-CoV-2 represent highly effective antiviral candidates for the treatment of infections, and are promisingly effective against current and future viral variants