Effects of different aperture-sized type I collagen/silk fibroin scaffolds on the proliferation and differentiation of human dental pulp cells

This study aimed at evaluate the effects of different aperture-sized type I collagen/silk fibroin(CSF)scaffolds on the proliferation and differentiation of human dental pulp cells(HDPCs).The CSF scaffolds were designed with 3D mapping software Solidworks.Three different aperture-sized scaffolds(CSF1-CSF3)were prepared by low-temperature deposition 3D printing technology.The morphology was observed by scanning electron microscope(SEM)and optical coherence tomography.The porosity,hydrophilicity and mechanical capacity of the scaffold were detected,respectively.HDPCs(third passage,1105 cells)were seeded into each scaffold and investigated by SEM,CCK-8,alkaline phosphatase(ALP)activity and HE staining.The CSF scaffolds had porous structures with macropores and micropores.The macropore size of CSF1 to CSF3 was 421627 lm,579636 lm and 707643 lm,respectively.The porosity was 69.862.2%,80.162.8%and 86.563.3%,respectively.All these scaffolds enhanced the adhesion and proliferation of HDPCs.The ALP activity in the CSF1 group was higher than that in the CSF3 groups(P<0.01).HE staining showed HDPCs grew in multilayer within the scaffolds.CSF scaffolds significantly improved the adhesion and ALP activity of HDPCs.CSF scaffolds were promising candidates in dentine-pulp complex regeneration.

An amelogenin-based peptide hydrogel promoted the odontogenic differentiation of human dental pulp cells

Amelogenin can induce odontogenic differentiation of human dental pulp cells(HDPCs),which has great potential and advantages in dentine-pulp complex regeneration.However,the unstability of amelogenin limits its further application.This study constructed amelogenin self-assembling peptide hydrogels(L-gel or D-gel)by heating-cooling technique,investigated the effects of these hydrogels on the odontogenic differentiation of HDPCs and explored the underneath mechanism.The critical aggregation concentration,conformation,morphology,mechanical property and biological stability of the hydrogels were characterized,respectively.The effects of the hydrogels on the odontogenic differentiation of HDPCs were evaluated via alkaline phosphatase activity measurement,quantitative reverse transcription polymerase chain reaction,western blot,Alizarin red staining and scanning electron microscope.The mechanism was explored via signaling pathway experiments.Results showed that both the L-gel and D-gel stimulated the odontogenic differentiation of HDPCs on both Day 7 and Day 14,while the D-gel showed the highest enhancement effects.Meanwhile,the D-gel promoted calcium accumulation and mineralized matrix deposition on Day 21.The D-gel activated MAPK-ERK1/2 pathways in HDPCs and induced the odontogenic differentiation via ERK1/2 and transforming growth factor/smad pathways.Overall,our study demonstrated that the amelogenin peptide hydrogel stimulated the odontogenic differentiation and enhanced mineralization,which held big potential in the dentine-pulp complex regeneration.

A bifunctional MXene-modified scaffold for photothermal therapy and maxillofacial tissue regeneration

Oral squamous cell carcinoma is one of the most common malignant tumours in the oral and maxillofacial regions and is highly malignant and prone to recur despite the development of various effective treatments,including surgery and chemoradiotherapy.Actually,it is difficult to ensure the complete elimination of tumour cells,and maxillofacial bone defects caused by surgery are hard to heal by themselves.In addition,chemoradiotherapy can bring serious side-effects.Therefore,it is imperative to develop a postoperative therapy to kill residual squamous cancer cells and repair bone defects without any side-effects.Here,we prepared a 3D scaffold by a 3D printing technique and freeze-drying method,which contained collagen,silk and hydroxyapatite(CSH)and was functionalized with MXene nanosheets(M-CSH).The considerable photothermal effect with long-term stability can significantly kill squamous CAL-27 cancer cells in vitro and inhibit tumour growth in vivo,increasing the probability of the M-CSH scaffold being applied in the photothermal therapy of oral squamous cell carcinoma.Moreover,the cell proliferation-and osteogenic-related protein expression of mouse embryonic osteogenic precursors(MC3T3-E1)indicated excellent biocompatibility and osteogenic activity of M-CSH scaffolds.The good compression modulus(52.8362.25 kPa)and in vivo bone formation performance made it possible to be used as reconstructive materials for bone defects.This scaffold is likely promising in future tissue engineering,especially for the multifunctional treatment of maxillofacial tumours.