Regulatory mechanisms and regeneration strategies of the soft-hard tissue interface in the human periodontium

The soft-hard tissue interface of the human periodontium is responsible for periodontal homeostasis and is essential for normal oral activities.This softhard tissue interface is formed by the direct insertion of fibrous ligaments into the bone tissue.It differs from the unique four-layer structure of the fibrocartilage interface.This interface is formed by a combination of physical,chemical,and biological factors.The physiological functions of this interface are regulated by different signaling pathways.The unique structure of this soft-hard tissue interface has inspired scientists to construct biomimetic gradient structures.These biomimetic systems include nanofiber scaffolds,cell sheets,and hydrogels.Exploring methods to repair this soft-hard tissue interface can help solve clinically unresolved problems.The present review examines the structure of the soft-hard tissue interface of the periodontium and the factors that influence the development of this interface.Relevant regulatory pathways and biomimetic reconstruction methods are also presented to provide ideas for future research on interfacial tissue engineering.

Atypical artificial cells:Novel biomimetic materials for combating cancer

The functional concept of using synthetic entities to supplement or replace certain functions or structures of biological cells is realized by the development of atypical artificial cells using a bottom-up approach.Tremendous progress has been achieved over the past 5 years that focuses on the therapeutic applications of atypical artificial cells,especially in the anticancer arena.Artificial cell-based anticancer strategies have demon-strated eminent advantages over conventional anticancer tactics,with excellent biocompatibility and targeting capability.The present review commences with introducing the constructing principles and classification of artificial cells.Artificial cell-based applications in cancer prophylaxis,diagnosis,and treatment are subsequently highlighted.These stimulating outcomes may inspire the development of next-generation anticancer ther-apeutic strategies.

Biomaterials from the sea:Future building blocks for biomedical applications

Marine resources have tremendous potential for developing high-value biomaterials.The last decade has seen an increasing number of biomaterials that originate from marine organisms.This field is rapidly evolving.Marine biomaterials experience several periods of discovery and development ranging from coralline bone graft to polysaccharide-based biomaterials.The latter are represented by chitin and chitosan,marine-derived collagen,and composites of different organisms of marine origin.The diversity of marine natural products,their properties and applications are discussed thoroughly in the present review.These materials are easily available and possess excellent biocompatibility,biodegradability and potent bioactive characteristics.Important applications of marine biomaterials include medical applications,antimicrobial agents,drug delivery agents,anticoagulants,rehabilitation of diseases such as cardiovascular diseases,bone diseases and diabetes,as well as comestible,cosmetic and industrial applications.

Engineered extracellular vesicles:Regulating the crosstalk between the skeleton and immune system

Osteoimmunology has gained momentum in recent years,focusing on the crosstalk between the skeleton and the immune system.Extracellular vesicles(EVs)are nanoscale vesicles that are potential candidates for cell-free tissue regeneration strategies.They may be used for repairing damaged tissues and regulating the body’s immune system and bone-related metabolic activities.Because of the ability of EVs to deliver bioactive signals and mediate intercellular communication,they can decipher the complex mechanisms of interaction within the“osteoimmune system”at the molecular level.To address the lack of targeting ability caused by vesicle heterogeneity in the clinical applications of EVs,these nanoscopical entities may be modified by bioengineering techniques to optimize the interaction between bone repair and immunomodulation for improving treatment efficacy,specificity and safety.In the present review,the endogenous properties that make EVs natural delivery agents are outlined.Properties that may be improved by bioengineering are highlighted.The therapeutic applications of EVs in the rehabilitation of bone defects are discussed.The opportunities and challenges that need to be addressed for translating this field of research into clinical practice are brought into perspectives.