Integrated-omics profiling unveils the disparities of host defense to ECM scaffolds during wound healing in aged individuals.

Extracellular matrix (ECM) scaffold membranes have exhibited promising potential to better the outcomes of wound healing by creating a regenerative microenvironment around. However, when compared to the application in younger individuals, the performance of the same scaffold membrane in promoting re-epithelialization and collagen deposition was observed dissatisfying in aged mice. To comprehensively explore the mechanisms underlying this age-related disparity, we conducted the integrated analysis, combing single-cell RNA sequencing (scRNA-Seq) with spatial transcriptomics, and elucidated six functionally and spatially distinctive macrophage groups and lymphocytes surrounding the ECM scaffolds. Through intergroup comparative analysis and cell-cell communication, we characterized the dysfunction of Spp1+ macrophages in aged mice impeded the activation of the type Ⅱ immune response, thus inhibiting the repair ability of epidermal cells and fibroblasts around the ECM scaffolds. These findings contribute to a deeper understanding of biomaterial applications in varied physiological contexts, thereby paving the way for the development of precision-based biomaterials tailored specifically for aged individuals in future therapeutic strategies.

Physiochemical Responses and Ecological Adaptations of Peach to Low-Temperature Stress: Assessing the Cold Resistance of Local Peach Varieties from Gansu, China.

In recent years, extreme weather events have become increasingly frequent, and low winter temperatures have had a significant impact on peach cultivation. The selection of cold-resistant peach varieties is an effective solution to mitigate freezing damage. To comprehensively and accurately evaluate the cold resistance of peaches and screen for high cold resistance among Gansu local resources, nine different types of peach were selected as test resources to assess physiological, biochemical, and anatomical indices. Subsequently, 28 peach germplasms were evaluated using relevant indices. The semi-lethal temperature (LT50) was calculated by fitting the change curve of the electrolyte leakage index (ELI) with the Logistic equation; this can be used as an important index for identifying and evaluating the cold resistance of peach trees. The LT50 values ranged from -28.22 °C to -17.22 °C among the 28 tested resources; Dingjiaba Liguang Tao exhibited the lowest LT50 value at -28.22 °C, indicating its high level of cold resistance. The LT50 was positively correlated with the ELI and malondialdehyde (MDA) content with correlation coefficients of 0.894 and 0.863, respectively, while it was negatively correlated with the soluble sugar (SS), soluble protein (SP), and free proline (Pro) contents with correlation coefficients of -0.894, -0.721, and -0.863, respectively. The thicknesses of the xylem, cork layer, cork layer ratio (CLR) and thickness/cortex thickness (X/C) showed negative correlations (-0.694, -0.741, -0.822, -0.814, respectively). Finally, the membership function method was used to evaluate cold resistance based on the ELI, MDA, Pro, SP, SS, CLR, and xylem thickness/cortex thickness (X/C) indices. The average membership degree among all tested resources ranged from 0.17 to 0.61. Dingjiaba Liguang Tao emerged prominently in terms of high-cold-resistance (HR) membership value (0.61).

Tracing immune cells around biomaterials with spatial anchors during large-scale wound regeneration.

Skin scarring devoid of dermal appendages after severe trauma has unfavorable effects on aesthetic and physiological functions. Here we present a method for large-area wound regeneration using biodegradable aligned extracellular matrix scaffolds. We show that the implantation of these scaffolds accelerates wound coverage and enhances hair follicle neogenesis. We perform multimodal analysis, in combination with single-cell RNA sequencing and spatial transcriptomics, to explore the immune responses around biomaterials, highlighting the potential role of regulatory T cells in mitigating tissue fibrous by suppressing excessive type 2 inflammation. We find that immunodeficient mice lacking mature T lymphocytes show the typical characteristic of tissue fibrous driven by type 2 macrophage inflammation, validating the potential therapeutic effect of the adaptive immune system activated by biomaterials. These findings contribute to our understanding of the coordination of immune systems in wound regeneration and facilitate the design of immunoregulatory biomaterials in the future.

The diameter factor of aligned membranes facilitates wound healing by promoting epithelialization in an immune way.

Topographical properties, such as pattern and diameter, of biomaterials play important roles in influencing cell activities and manipulating the related immune response during wound healing. We prepared aligned electrospinning membranes with different fiber diameters, including 319 ± 100 nm (A300), 588 ± 132 nm (A600), and 1048 ± 130 nm (A1000), by adjusting the distance from the tip to the collector, the injection rate, and the concentration of the solution. The A300 membranes significantly improved cell proliferation and spreading and facilitated wound healing (epithelization and vascularization) with the regeneration of immature hair follicles compared to the other membranes. Transcriptomics revealed the underlying molecular mechanism that A300 could promote immune-related processes towards a pro-healing direction, significantly promoting keratinocyte migration and skin wound healing. All the results indicated that wound healing requires the active participation of the immune process, and that A300 was a potential candidate for guided skin regeneration applications.

Horizontal bone augmentation of the edentulous area with simultaneous endodontic microsurgery of the adjacent tooth: A digitally-driven multidisciplinary case report with a 1-year follow-up.

PURPOSE: To introduce a novel and efficient procedure to solve a multidisciplinary issue connected to implant-related surgery in areas near periapical lesions of adjacent teeth using single-stage combined surgery while exploring a new way to prevent retrograde peri-implantitis. MATERIALS AND METHODS: A 31-year-old woman diagnosed with a Kennedy III dentition defect in the maxillary right central incisor and posttreatment apical periodontitis in the maxillary right lateral incisor was treated using a multidisciplinary procedure. First, the preoperative data were collected from intraoral, extraoral facial and CBCT scans. Then, the aesthetic appearance of the anterior teeth was planned digitally and implant insertion was simulated. Next, virtual bone augmentation was carried out with reference to the simulated implant position, and according to the virtual augmentation, the templates for bone shell harvesting (also used for apical osteotomy and root tip resection during endodontic microsurgery) and bone shell grafting of the edentulous area were designed and fabricated. The templates for combined surgery (endodontic microsurgery and horizontal bone augmentation) consisted of one basal template and multiple interchangeable attachments via a plugin design to make guided endodontic microsurgery and digitally guided bone augmentation more efficient. Combined surgery was then carried out using the templates for guidance. During surgery, the apical inflammation affecting the maxillary right lateral incisor was first removed and its preserved apical bony window was prepared as an autogenous bone shell for bone augmentation of the maxillary right central incisor site. Guided bone regeneration of the edentulous area and guided tissue regeneration were then performed for the adjacent tooth. Six months after the combined surgery, digital guided implant surgery was carried out for the edentulous area. The final prosthesis was delivered in accordance with the preoperative aesthetic design and achieved using an implant-supported restoration for the maxillary right central incisor, full crown restoration for the maxillary right lateral incisor, and ceramic veneers for the maxillary left central and lateral incisors for space closure. RESULTS: The horizontal bone augmentation in the edentulous area and endodontic microsurgery on the neighbouring tooth were performed successfully in a single-stage surgical procedure; thus, augmentation of the resorbed alveolar bone and removal of infection in the adjacent site were achieved simultaneously. At the 1-year follow-up after combined surgery, the healing of the natural maxillary right lateral incisor and the area having undergone bone augmentation showed promising results with no postoperative complications. CONCLUSIONS: This novel digital workflow appears effective in addressing the problem of periapical lesions in retained teeth adjacent to the edentulous area that requires horizontal bone augmentation in one surgical procedure, providing an efficient way of resolving the problem using endodontics and implantology, and preventing retrograde peri-implantitis.

Dissecting the microenvironment around biosynthetic scaffolds in murine skin wound healing.

The structural properties of biomaterials play crucial roles in guiding cell behavior and influencing immune responses against the material. We fabricated electrospun membranes with three types of surface topography (random, aligned, and latticed), introduced them to dorsal skin excisional wounds in mice and rats, and evaluated their effects on wound healing and immunomodulatory properties. An overview of different immune cells in the microenvironment with the help of single-cell RNA sequencing revealed diverse cellular heterogeneity in vivo. The time course of immune response was advanced toward an adaptive immunity-dominant stage by the aligned scaffold. In mice without mature T lymphocytes, lack of wound-induced hair neogenesis indicated a regulatory role of T cells on hair follicle regeneration. The microenvironment around scaffolds involved an intricate interplay of immune and cutaneous cells.

Study on osteogenesis of zinc-loaded carbon nanotubes/chitosan composite biomaterials in rat skull defects.

Chitosan with hydroxyapatite composition, a natural polymer, may be a biomaterial of importance for bone regeneration. Carbon nanotube, a nanoscale material, has been another focus for bone restoration. Zinc, an essential trace element, contributes to the development and growth of skeletal system. The purpose of the current research was to investigate the effects of Zinc-loaded Carbon Nanotubes/Chitosan composite biomaterials in the restoration of rat skull defects, and to verify the hypothesis that these zinc ions of appropriate concentration would strengthen the osteogenesis of rat defects. Four different groups of composite biomaterials were fabricated from no Zinc Carbon nanotubes/Chitosan (GN), 0.2% Zinc-Carbon nanotubes/Chitosan (GL), 1% Zinc-Carbon nanotubes/Chitosan (GM) and 2% Zinc-Carbon nanotubes/Chitosan (GH). After characterizations, these composite biomaterials were then transplanted into rat skull defects. The experimental animals were executed at 12 weeks after transplanted surgeries, and the rat skull defects were removed for related analyses. The results of characterizations suggested the Zinc-loaded composite biomaterials possessed good mechanical and osteoinductive properties. An important finding was that the optimal osteogenic effect appeared in rat skull defects transplanted with 1% Zinc-Carbon nanotubes/Chitosan. Overall, these composite biomaterials revealed satisfactory osteogenesis, nevertheless, there was a requirement to further perfect the zinc ion concentrations to achieve the better bone regeneration.

Diverse effects of platelet-derived growth factor-BB on cell signaling pathways.

Platelet-derived growth factor-BB (PDGF-BB) is involved in the tissue repair and tumor progression effects, and act as a rapid and early effector cytokines which are released in response to pathogen-induced changes in the microenvironment. Recent researches have implicated PDGF-BB as a potential contributing factor to the spectrum of the cell signaling pathway of interrelated diseases, particularly mesangial cells, mesenchymal stem cells, human dermal fibroblasts, tumor pericytes and smooth muscle cells. In this review, we generalize the present literatures on the roles of PDGF-BB in the various interrelated diseases, providing insights or strategies into the underlying cellular and signaling mechanisms that will help guide future studies further into promising interventional targets with therapeutic potential.