NK cell based immunotherapy against oral squamous cell carcinoma.

Oral squamous cell carcinoma (OSCC), a major subtype of head and neck cancers, presents significant challenges due to its aggressive feature and limited therapeutic efficacy of conventional treatments. In response to these challenges, Natural Killer (NK) cells, a vital component of the innate immune system, are being explored for their therapeutic potential in OSCC due to their inherent ability to target and eliminate cancer cells without prior sensitization. This review uniquely focuses on the evolving role of NK cells specifically in OSCC, incorporating recent advancements in CAR-NK cell engineering and personalized therapy approaches that have not been comprehensively covered in previous reviews. The mechanisms through which NK cells exert cytotoxic effects on tumor cells include direct killing through the engagement of natural cytotoxic receptors and antibody-dependent cellular cytotoxicity (ADCC), making them promising agents in cancer immunotherapy. Additionally, the article explores recent advancements in engineering NK cells to enhance their antitumor activity, such as the modification with chimeric antigen receptors (CARs) to target specific tumor antigens. Clinical implications of NK cell-based therapies, including the challenges of integrating these treatments with existing protocols and the potential for personalized therapy, are examined. The review highlights the promise of NK cell therapies in improving outcomes for OSCC patients and outlines future directions for research in this dynamic field of oncological immunotherapy.

The durability of resin-dentine bonds are enhanced by epigallocatechin-3-gallate-encapsulated nanohydroxyapatite/mesoporous silica.

Biomimetic nanohydroxyapatite (nHAp) has long been used as a biocompatible material for bone repair, bone regeneration, and bone reconstruction due to its low toxicity to local or systemic tissues. Various cross-linkers have been employed to maintain the structure of collagen; these include epigallocatechin-3-gallate (EGCG), which can fortify the mechanical properties of collagen and withstand the degradation of collagenase. We hypothesized that EGCG combined with nHAp may promote resin-dentin bonding durability. Here, we examined the effect of epigallocatechin-3-gallate-encapsulated nanohydroxyapatite/mesoporous silica (EGCG@nHAp@MSN) on thermal stability and remineralization capability of dentin collagen. Dentin slices (2 × 2 × 1 mm3 ) were obtained and completely demineralized in a 10% phosphoric acid water solution. The resulting dentin collagen matrix was incubated with deionized water, EGCG, nHAp@MSN, and EGCG@nHAp@MSN. The collagen thermal degradation temperature was assessed utilizing differential scanning calorimetry analysis, which indicated that EGCG, nHAp@MSN, and EGCG@nHAp@MSN reinforced collagen's capability to resist thermal degradation. EGCG@nHAp@MSN resulted in the highest increase in denaturation temperature. Thermogravimetric analysis showed that both nHAp@MSN and EGCG@nHAp@MSN achieved a higher residual mass than the EGCG and control groups. Fourier transform infrared spectroscopy was performed to examine the interaction between EGCG@nHAp@MSN and dentin collagen. The EGCG@nHAp@MSN sample exhibited stronger dentin microhardness and uppermost bond strength after thermocycling. EGCG significantly enhanced collagen's capability to resist thermal degradation. In summary, EGCG and nHAp@MSN may work together to assist the exposed collagen to improve resistance to thermal cycling and promote remineralization while also strengthening the durability of resin-dentin bonds.

Procyanidin B2 inhibits angiogenesis and cell growth in oral squamous cell carcinoma cells through the vascular endothelial growth factor (VEGF)/VEGF receptor 2 (VEGFR2) pathway.

This study aimed to explore the therapy role of procyanidin B2 (PB2) in inhibiting angiogenesis and cell growth in oral squamous cell carcinoma. After oral mucosa epithelial cell (OMEC) and human oral squamous cell carcinoma (OSCC) cell line (SCC-25) were treated with PB2 or SCC-25 were treated with PB2 and rhVEGF, cell counting kit-8 (CCK-8) assay was used to determine the cell viability. The apoptosis, migration, invasion and angiogenesis of SCC-25 after indicated treatment were detected by Tunel, wound healing, transwell and tube formation assays. The protein expression related to apoptosis, metastasis and epithelial-mesenchymal transition (EMT) and changed expression of vascular endothelial growth factor (VEGF)/VEGF receptor 2 (VEGFR2) signaling was analyzed by Western blot. As a result, PB2 inhibited viability, invasion, migration and EMT and promoted apoptosis of SCC-25 cells. In addition, PB2 inhibited VEGF/VEGFR2 signaling and tumor itangiogenesis in OSCC. As expected, activation of VEGF/VEGFR2 signaling suppressed the effect of PB2 on growth and metastasis of OSCC cells. In conclusion, PB2 inhibited the VEGF/VEGFR2 pathway to suppress the angiogenesis and cell growth of SCC-25 cells.

Intrafibrillar mineralization of polyacrylic acid-bound collagen fibrils using a two-dimensional collagen model and Portland cement-based resins.

The biomimetic remineralization of apatite-depleted dentin is a potential method for enhancing the durability of resin-dentin bonding. To advance this strategy from its initial proof-of-concept design, we sought to investigate the characteristics of polyacrylic acid (PAA) adsorption to desorption from type I collagen and to test the mineralization ability of PAA-bound collagen. Portland cement and ß-tricalcium phosphate (ß-TCP) were homogenized with a hydrophilic resin blend to produce experimental resins. The collagen fibrils reconstituted on nickel (Ni) grids were mineralized using different methods: (i) group I consisted of collagen treated with Portland cement-based resin in simulated body fluid (SBF); (ii) group II consisted of PAA-bound collagen treated with Portland cement-based resin in SBF; and (iii) group III consisted of PAA-bound collagen treated with ß-TCP-doped Portland cement-based resin in deionized water. Intrafibrillar mineralization was evaluated using transmission electron microscopy. We found that a carbonyl-associated peak at pH 3.0 increased as adsorption time increased, whereas a hydrogen bond-associated peak increased as desorption time increased. The experimental resins maintained an alkaline pH and the continuous release of calcium ions. Apatite was detected within PAA-bound collagen in groups II and III. Our results suggest that PAA-bound type I collagen fibrils can be mineralized using Portland cement-based resins.

[Biomodifying effect of epigallocatechin-3-gallate on dentine substrate splicing surface].

OBJECTIVE: To investigate the effect of epigallocatechin-3-gallate (EGCG) on biomodification of demineralized dentine substrate, in its permeability, hydrophobicity, and inhibition ability to collagen enzymatic degradation. METHODS: The dentine substrates were treated with simulated pulpal pressure created by mixtures of 0.02%, 0.1% EGCG/bovine serum albumin (BSA) in acidic environment (pH4.4) for 48 h. A fluid-transport model was used to measure the fluid permeability through demineralized dentine substrate. Positive replicas of dentine substrate were fabricated before and after being subjected to acidic environment for scanning electron microscope (SEM) examination. The blank group contained no EGCG and the positive group were treated with Gluma desensitizer. Static contact angle measurements on demineralized dentin and 0.1% EGCG primed dentin were performed by contact angle analyzer. The priming time were 60 s, 120 s, 0.5 h, 1 h. Dentine specimens bonded with Adper single bond 2 were subjected to 100 mg/L collagenase and observed under SEM. Resin-bonded specimens (with 0.02%, 0.1%, 0.5% EGCG priming, or without EGCG priming) were created for micro-tensile bond strength evaluation (MTBS). Resin-bonded specimens after thermol cycling were created for MTBS evaluation. RESULTS: The fluid permeability in the blank control group increased ([151.3±22.3]%), the fluid permeability in 0.1% EGCG/BSA group decreased ([23.7±6.3]%). Compared to the blank control group, the contact angle of 120 s, 0.5 h, 1 h groups increased by 31.0%, 53.5%, 57.8% in deep dentin and 37.4%, 59.3%, 62.4% in shallow dentin. The SEM examination showed that 0.1% and 0.5% EGCG priming for 120 s significantly increased dentin collagen's resistance to collagenase. The immediate MTBS of 0.1% and 0.5% EGCG groups were (29.4±4.8) and (19.8± 4.9) MPa. After thermol cycling, the MTBS of 0.1% and 0.5% EGCG groups were (19.9±5.1) and (15.3± 6.3) MPa. CONCLUSIONS: Under acidic environment (pH4.4), the 0.1% EGCG can reduce dentine permeability under acidic environment. The 0.1% EGCG can increase hydrophobicity of dentin substrate, and strengthen dentin substrate's resistance to collagenase hydrolysis, thus increased the resin-dentin bonding durability.

[Sealing properties of three resin-based sealers].

OBJECTIVE: To evaluate the sealing properties of three resin- based sealers, EndoREZ, RealSEAL and RealSEAL SE. METHODS: Forthy-eight extracted human anterior teeth with single root and canal were prepared using ProTaper files with crown-down technique to F3. The teeth were filled with three sealer respectively with hot gutta- percha vertical condensation technique simulating the clinical situation. Leakage quantity was detected using computerized fluid filtration meter with 10 samples in each group. The cross section morphology of apical parts of roots of 5 mm was observed with scanning electron microscope and transmission electron microscope in 3 samples of each group, respectively. RESULTS: The leakage quantity of EndoREZ, RealSEAL and RealSEAL SE were (2.61±0.60), (1.43±0.11) and (1.76±0.18) µl/min, respectively. The gaps between the the sealer and the canal wall were increased in in order of RealSEAL, RealSEAL SE and EndoREZ. No obvious demineralized dentin under EndoREZ and the smear layer was not completed removed. The partly demineralized dentin was observed under RealSEAL and the smear layer was totally removed. The partly demineralized dentin was seen under RealSEAL SE and the majority of smear layer was removed. CONCLUSIONS: Among the three resin- based sealers, RealSEAL has the best sealing properties, followed by RealSEAL SE and EndoREZ.