ObjectiveTo compare therapeutic effects of the bone-guided tissue regeneration in combination with a composite bovine-derived xenograft versus flap surgery only on intra-bony defects in elderly patients with periodontal disease. MethodsThirty elderly patients with periodontal disease were randomly divided into two groups. One group was treated by the bone-guided tissue regeneration in combination with a composite bovine-derived xenograft (experimental group). The other group was treated by flap surgery only (control group). Probing depth (PD)and clinical attachment level (AL) were determined before surgery and six months after treatment in two groups. The change of bone amount was also determined before surgery and six months after treatment through computer-assisted densitometric image analysis(CADIA). ResultsThe changes of PD and CADIA were (3.8+1.7)mm, (20. 3+11.1)g/mm2 in experimental group and were (2.5+1.1)mm, (9.4+8. 6)g/mm2 in control group. The differences between two groups were significant (P.＜0. 05). The change of AL was (3.5+ 1.6)mm in experimental group, compared with control group(2. 3 1.7)mm, which showed more obvious regeneration of alveolar bone (P＜ 0. 01). ConclusionsGuided tissue regeneration in combination with a composite bovine-derived xenograft appears to be more effective than flap surgery only for intra-bony defects in elderly patients with periodontal disease.

After implantation of a biomaterial, both the host immune system and properties of the material determine the local immune response. Through triggering or modulating the local immune response, materials can be designed towards a desired direction of promoting tissue repair or regeneration. High-throughput sequencing technologies such as single-cell RNA sequencing (scRNA-seq) emerging as a powerful tool for dissecting the immune micro-environment around biomaterials, have not been fully utilized in the field of soft tissue regeneration. In this review, we first discussed the procedures of foreign body reaction in brief. Then, we summarized the influences that physical and chemical modulation of biomaterials have on cell behaviors in the micro-environment. Finally, we discussed the application of scRNA-seq in probing the scaffold immune micro-environment and provided some reference to designing immunomodulatory biomaterials. The foreign body response consists of a series of biological reactions. Immunomodulatory materials regulate immune cell activation and polarization, mediate divergent local immune micro-environments and possess different tissue engineering functions. The manipulation of physical and chemical properties of scaffolds can modulate local immune responses, resulting in different outcomes of fibrosis or tissue regeneration. With the advancement of technology, emerging techniques such as scRNA-seq provide an unprecedented understanding of immune cell heterogeneity and plasticity in a scaffold-induced immune micro-environment at high resolution. The in-depth understanding of the interaction between scaffolds and the host immune system helps to provide clues for the design of biomaterials to optimize regeneration and promote a pro-regenerative local immune micro-environment.