Surface modification strategies to reinforce the soft tissue seal at transmucosal region of dental implants

Soft tissue seal around the transmucosal region of dental implants is crucial for shielding oral bacterial invasion and guaranteeing the long-term functioning of implants.Compared with the robust periodontal tissue barrier around a natural tooth,the peri-implant mucosa presents a lower bonding efficiency to the transmucosal region of dental implants,due to physiological structural differences.As such,the weaker soft tissue seal around the transmucosal region can be easily broken by oral pathogens,which may stimulate serious inflammatory responses and lead to the development of peri-implant mucositis.Without timely treatment,the curable peri-implant mucositis would evolve into irreversible peri-implantitis,finally causing the failure of implantation.Herein,this review has summarized current surface modification strategies for the transmucosal region of dental implants with improved soft tissue bonding capacities(e.g.,improving surface wettability,fabricating micro/nano topographies,altering the surface chemical composition and constructing bioactive coatings).Furthermore,the surfaces with advanced soft tissue bonding abilities can be incorporated with antibacterial properties to prevent infections,and/or with immunomodulatory designs to facilitate the establishment of soft tissue seal.Finally,we proposed future research orientations for developing multifunctional surfaces,thus establishing a firm soft tissue seal at the transmucosal region and achieving the long-term predictability of dental implants.

A scaffold vaccine to promote tumor antigen cross-presentation via sustained toll-like receptor-2(TLR2)activation

Cancer vaccination holds great promise for cancer treatment,but its effectiveness is hindered by suboptimal activation of CD8+cytotoxic T lymphocytes,which are potent effectors to mediate anti-tumor immune responses.A possible solution is to switch antigen-presenting cells to present tumor antigens via the major histocompatibility complex class I(MHC-I)to CD8+T cells-a process known as cross-presentation.To achieve this goal,we develop a three-dimensional(3D)scaffold vaccine to promote antigen cross-presentation by persisted toll-like receptor-2(TLR2)activation after one injection.This vaccine comprises polysaccharide frameworks that“hook”TLR2 agonist(acGM)via tunable hydrophobic interactions and forms a 3D macroporous scaffold via click chemistry upon subcutaneous injection.Its retention-and-release of acGM enables sustained TLR2 activation in abundantly recruited dendritic cells in situ,inducing intracellular production of reactive oxygen species(ROS)in optimal kinetics that crucially promotes efficient antigen cross-presentation.The scaffold loaded with model antigen ovalbumin(OVA)or tumor specific antigen can generate potent immune responses against lung metastasis in B16-OVA-innoculated wild-type mice or spontaneous colorectal cancer in transgenic ApcMin/+mice,respectively.Notably,it requires neither additional adjuvants nor external stimulation to function and can be adjusted to accommodate different antigens.The developed scaffold vaccine may represent a new,competent tool for next-generation personalized cancer vaccination.