Spartina alterniflora invasion benefits blue carbon sequestration in China.

Spartina alterniflora has rapidly and extensively encroached on China's coastline over the past decades. Among the coastal areas invaded by S. alterniflora, at most 93% are mudflats. However, the effect of S. alterniflora invasion on soil organic carbon (SOC) stocks of coastal mudflats has not been systematically studied on a national scale. Here, we quantified the nationwide changes in SOC stocks in coastal mudflats associated with S. alterniflora invasion between 1990 and 2020. We found that S. alterniflora invasion significantly enhanced SOC stocks in coastal China. Nonetheless, the benefit of S. alterniflora invasion of coastal SOC stock may be weakened by continuing human intervention. We found that S. alterniflora invading mudflats added 2.3 Tg SOC stocks to China's coastal blue carbon, while 1.78 Tg SOC stocks were lost mainly due to human activities, resulted in a net SOC stock gain of 0.52 Tg C. These findings overturned the traditionally thought that S. alterniflora invasion would reduce ecosystem services by highlighting that the historical invasion of S. alterniflora has broadly and consistently enhanced blue carbon stock in coastal China.

Polyvalent mpox mRNA vaccines elicit robust immune responses and confer potent protection against vaccinia virus.

The 2022 mpox outbreak led the World Health Organization (WHO) to declare it a public health emergency of international concern (PHEIC). There is a need to develop more effective and safer mpox virus (MPXV)-specific vaccines in response to the mpox epidemic. The mRNA vaccine is a promising platform to protect against MPXV infection. In this study, we construct two bivalent MPXV mRNA vaccines, designated LBA (B6R-A29L) and LAM (A35R-M1R), and a quadrivalent mRNA vaccine, LBAAM (B6R-A35R-A29L-M1R). The immunogenicity and protective efficacy of these vaccines alone or in combination were evaluated in a lethal mouse model. All mRNA vaccine candidates could elicit potential antigen-specific humoral and cellular immune responses and provide protection against vaccinia virus (VACV) infection. The protective effect of the combination of two bivalent mRNA vaccines and the quadrivalent vaccine was superior to that of the individual bivalent mRNA vaccine. Our study provides valuable insights for the development of more efficient and safer mRNA vaccines against mpox.

Circular RNA vaccines against monkeypox virus provide potent protection against vaccinia virus infection in mice.

Since the outbreak of monkeypox (mpox) in 2022, widespread concern has been placed on imposing an urgent demand for specific vaccines that offer safer and more effective protection. Using an efficient and scalable circular RNA (circRNA) platform, we constructed four circRNA vaccines that could induce robust neutralizing antibodies as well as T cell responses by expressing different surface proteins of mpox virus (MPXV), resulting in potent protection against vaccinia virus (VACV) in mice. Strikingly, the combination of the four circular RNA vaccines demonstrated the best protection against VACV challenge among all the tested vaccines. Our study provides a favorable approach for developing MPXV-specific vaccines by using a circular mRNA platform and opens up novel avenues for future vaccine research.

A potential bivalent mRNA vaccine candidate protects against both RSV and SARS-CoV-2 infections.

As the world continues to confront severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), respiratory syncytial virus (RSV) is also causing severe respiratory illness in millions of infants, elderly individuals, and immunocompromised people globally. Exacerbating the situation is the fact that co-infection with multiple viruses is occurring, something which has greatly increased the clinical severity of the infections. Thus, our team developed a bivalent vaccine that delivered mRNAs encoding SARS-CoV-2 Omicron spike (S) and RSV fusion (F) proteins simultaneously, SF-LNP, which induced S and F protein-specific binding antibodies and cellular immune responses in BALB/c mice. Moreover, SF-LNP immunization effectively protected BALB/c mice from RSV infection and hamsters from SARS-CoV-2 Omicron infection. Notably, our study pointed out the antigenic competition problem of bivalent vaccines and provided a solution. Overall, our results demonstrated the potential of preventing two infectious diseases with a single vaccine and provided a paradigm for the subsequent design of multivalent vaccines.

Coastal blue carbon in China as a nature-based solution toward carbon neutrality.

To achieve the Paris Agreement, China pledged to become "Carbon Neutral" by the 2060s. In addition to massive decarbonization, this would require significant changes in ecosystems toward negative CO2 emissions. The ability of coastal blue carbon ecosystems (BCEs), including mangrove, salt marsh, and seagrass meadows, to sequester large amounts of CO2 makes their conservation and restoration an important "nature-based solution (NbS)" for climate adaptation and mitigation. In this review, we examine how BCEs in China can contribute to climate mitigation. On the national scale, the BCEs in China store up to 118 Tg C across a total area of 1,440,377 ha, including over 75% as unvegetated tidal flats. The annual sedimental C burial of these BCEs reaches up to 2.06 Tg C year-1, of which most occurs in salt marshes and tidal flats. The lateral C flux of mangroves and salt marshes contributes to 1.17 Tg C year-1 along the Chinese coastline. Conservation and restoration of BCEs benefit climate change mitigation and provide other ecological services with a value of $32,000 ha-1 year-1. The potential practices and technologies that can be implemented in China to improve BCE C sequestration, including their constraints and feasibility, are also outlined. Future directions are suggested to improve blue carbon estimates on aerial extent, carbon stocks, sequestration, and mitigation potential. Restoring and preserving BCEs would be a cost-effective step to achieve Carbon Neutral by 2060 in China despite various barriers that should be removed.

Monitoring the in vivo siRNA release from lipid nanoparticles based on the fluorescence resonance energy transfer principle.

The siRNA-loaded lipid nanoparticles have attracted much attention due to its significant gene silencing effect and successful marketization. However, the in vivo distribution and release of siRNA still cannot be effectively monitored. In this study, based on the fluorescence resonance energy transfer (FRET) principle, a fluorescence dye Cy5-modified survivin siRNA was conjugated to nanogolds (Au-DR-siRNA), which were then wrapped with lipid nanoparticles (LNPs) for monitoring the release behaviour of siRNA in vivo. The results showed that once Au-DR-siRNA was released from the LNPs and cleaved by the Dicer enzyme to produce free siRNA in cells, the fluorescence of Cy5 would change from quenched state to activated state, showing the location and time of siRNA release. Besides, the LNPs showed a significant antitumor effect by silencing the survivin gene and a CT imaging function superior to iohexol by nanogolds. Therefore, this work provided not only an effective method for monitoring the pharmacokinetic behaviour of LNP-based siRNA, but also a siRNA delivery system for treating and diagnosing tumors.

Negatively charged nano-hydroxyapatite can be used as a phosphorus fertilizer to increase the efficacy of wollastonite for soil cadmium immobilization.

Improper application of phosphorus (P) fertilizer during soil cadmium (Cd) immobilization reduces the efficiency of fertilizer and Cd remediation. In this study, we synthesized three types of nano-hydroxyapatite (NHAP) with different surface charges as slow-release P fertilizers during Cd immobilization. We also evaluated the effects of wollastonite application with or without NHAP addition, in comparison with triple superphosphate (TSP) or bulk hydroxyapatite, on Cd accumulation in Amaranthus tricolor L. The results showed that adding wollastonite significantly reduced P availability (23.5%) in the soil, but it did not inhibit plant P uptake. In wollastonite-amended soil, the application of negatively/positively charged NHAP significantly increased plant biomass by 643-865% and decreased Cd uptake by 74.8-75.1% compared to the unamended soil as well as showed greater efficiency than those with TSP. This was ascribed to the increased soil pH (from 3.94 to 6.52-6.63) and increased abundance of organic acids (including citric acid, malic acid, lactic acid, and acetic acid) secreted by plants. In addition, the P-preferring bacterial class Bacteroidia was specific to soils amended with both wollastonite and NHAP-. These results suggest that NHAP- may be an appropriate P fertilizer for soil Cd immobilization using wollastonite.

Icariin-loaded hydrogel with concurrent chondrogenesis and anti-inflammatory properties for promoting cartilage regeneration in a large animal model.

Currently, an effective repair method that can promote satisfactory cartilage regeneration is unavailable for cartilage damages owing to inevitable inflammatory erosion. Cartilage tissue engineering has revealed considerable treatment options for cartilage damages. Icariin (ICA) is a flavonoid component of Epimedii folium with both chondrogenic and anti-inflammatory properties. In this study, we prepared an ICA/CTS hydrogel by loading ICA into chitosan (CTS) hydrogel to impart chondrogenesis and anti-inflammatory properties to the ICA/CTS hydrogel. In vitro results revealed that ICA showed sustained release kinetics from the ICA/CTS hydrogel. In addition, compared to the CTS hydrogel, the ICA/CTS hydrogel exhibited a favorable in vitro anti-inflammatory effect upon incubation with lipopolysaccharide pre-induced RAW264.7 macrophages, as indicated by the suppression of inflammatory-related cytokines (IL-6 and TNF-α). Additionally, when co-cultured with chondrocytes in vitro, the ICA/CTS hydrogel showed good cytocompatibility, accelerated chondrocyte proliferation, and enhanced chondrogenesis compared to the CTS hydrogel. Moreover, the in vitro engineered cartilage from the chondrocyte-loaded ICA/CTS hydrogel achieved stable cartilage regeneration when subcutaneously implanted in a goat model. Finally, the addition of ICA endowed the ICA/CTS hydrogel with a potent anti-inflammatory effect compared to what was observed in the CTS hydrogel, as confirmed by the attenuated IL-1ß, IL-6, TNF-α, and TUNEL expression. The prepared ICA/CTS hydrogel offered an effective method of delivery for chondrogenic and anti-inflammatory agents and served as a useful platform for cartilage regeneration in an immunocompetent large animal model.

Lipid nanoparticles produce chimeric antigen receptor T cells with interleukin-6 knockdown in vivo.

Chimeric receptor T cells (CAR-T) can effectively cure leukemia; however, there are two limitations: a complicated preparation process ex vivo and cytokine release syndrome (CRS). In this study, we constructed a lipid nanoparticle system modified by CD3 antibody on the surface, loading with the plasmid containing the combination gene of interleukin 6 short hairpin RNA (IL-6 shRNA) and CD19-CAR (AntiCD3-LNP/CAR19 + shIL6). The system targeted T cells by the mediation of CD3 antibody and stably transfected T cells to transform them into CAR-T cells with IL-6 knockdown, thus killing CD19-highly expressed leukemia tumor cells and reducing CRS caused by IL-6. In vivo experiments showed that AntiCD3-LNP/CAR19 + shIL6 could stably transfect T cells and produce CAR-T within 90 days to kill the tumor. This significantly prolonged the survival time of leukemia model mice and demonstrated the prepared LNP exhibited the same anti-tumor effect as the traditional CAR-T cells prepared ex vivo. In this study, CAR-T cells were directly produced in vivo after intravenous injection of the lipid nanoparticles, without the need of using the current complex process ex vivo. Additionally, IL-6 expression was silenced, which would be helpful to reduce the CRS and improve the safety of CAR-T therapy. This method improves the convenience of using CAR-T technology and is helpful in further promoting the clinical application of CAR-T.

CAR T cells equipped with a fully human scFv targeting Trop2 can be used to treat pancreatic cancer.

PURPOSE: Chimeric antigen receptor (CAR) T cell therapy has demonstrated clinical success in treating haematologic malignancies but has not been effective against solid tumours thus far. Trop2 is a tumour-related antigen broadly overexpressed on a variety of tumours and has been reported as a promising target for pancreatic cancers. Our study aimed to determine whether CAR T cells designed with a fully human Trop2-specific single-chain fragment variable (scFv) can be used in the treatment of Trop2-positive pancreatic tumours. METHODS: We designed Trop2-targeted chimeric antigen receptor engineered T cells with a novel human anti-Trop2 scFv (2F11) and then investigated the cytotoxicity, degranulation, and cytokine secretion profiles of the anti-Trop2 CAR T cells when they were exposed to Trop2 + cancer cells in vitro. We also studied the antitumour efficacy and toxicity of Trop2-specific CAR T cells in vivo using a BxPC-3 pancreatic xenograft model. RESULTS: Trop2-targeted CAR T cells designed with 2F11 effectively killed Trop2-positive pancreatic cancer cells and produced high levels of cytotoxic cytokines in vitro. In addition, Trop2-targeted CAR T cells, which persistently circulate in vivo and efficiently infiltrate into tumour tissues, significantly blocked and even eliminated BxPC-3 pancreatic xenograft tumour growth without obvious deleterious effects observed after intravenous injection into NSG mice. Moreover, disease-free survival was efficiently prolonged. CONCLUSION: These results show that Trop2-targeted CAR T cells equipped with a fully human anti-Trop2 scFv could be a potential treatment strategy for pancreatic cancer and could be useful for clinical evaluation.

Nitrogen and phosphorus addition exerted different influences on litter and soil carbon release in a tropical forest.

Terrestrial soils release large amount of carbon dioxide (CO2) each year, which are mainly derived from litter and soil carbon (C) decomposition. Nutrient availability, especially nitrogen (N) and phosphorus (P), plays an important role in both litter and soil C decomposition. Therefore, understanding the underlying mechanism is crucial for mitigating CO2 emission and climate changes. Here, we assessed patterns of litter and soil C decomposition after 11 yrs. in-situ N and P addition in a tropical forest where corn leaves or corn roots were added as litter C. The total CO2 efflux was quantified and partitioned using 13C isotope signatures to determine the sources (litter or soil C) every three months. In addition, Changes in C-degrading enzyme activities: ß-1,4-glucosidase (BG), phenol oxidase (PHO) and peroxidase (PER), and microbial biomarkers were assessed to interpret the underlying mechanism. Total C-release was enhanced up to17% by the long-term N addition but inhibited up to 15% by P addition. Precisely, N addition only accelerated the litter decomposition and increased about 42% and 6% of the litter C release at 0-5 cm and 5-10 cm soil depths, respectively; while P addition only impeded the soil C decomposition and decreased about 9% and 11% of the soil C release at 0-5 cm and 5-10 cm, respectively. The enhanced C release under N addition might be attributed to the enhanced microbial biomass, the ratio of fungi to bacteria and C-degrading enzyme activities. However, P addition resulted in the reverse result in microbial properties and C-degrading enzyme activities, associated with a decreased C release. Our study suggests that the long-term N and P addition selectively affected the litter and soil C decomposition because of their different physiochemical properties and this tendency might be more pronounced in tropical forests exposed to increasing atmospheric N deposition in the future. The study indicates that the different patterns of litter and soil C decomposition under climate change should be taken account in the future C management strategies.

Nanoengineered Neutrophils as a Cellular Sonosensitizer for Visual Sonodynamic Therapy of Malignant Tumors.

The rapid evolution of cell-based theranostics has attracted extensive attention due to their unique advantages in biomedical applications. However, the inherent functions of cells alone cannot meet the needs of malignant tumor treatment. Thus endowing original cells with new characteristics to generate multifunctional living cells may hold a tremendous promise. Here, the nanoengineering method is used to combine customized liposomes with neutrophils, generating oxygen-carrying sonosensitizer cells with acoustic functions, which are called Acouscyte/O2 , for the visual diagnosis and treatment of cancer. Specifically, oxygen-carried perfluorocarbon and temoporfin are encapsulated into cRGD peptide modified multilayer liposomes (C-ML/HPT/O2 ), which are then loaded into live neutrophils to obtain Acouscyte/O2 . Acouscyte/O2 can not only carry a large amount of oxygen but also exhibits the ability of long circulation, inflammation-triggered recruitment, and decomposition. Importantly, Acouscyte/O2 can be selectively accumulated in tumors, effectively enhancing tumor oxygen levels, and triggering anticancer sonodynamics in response to ultrasound stimulation, leading to complete obliteration of tumors and efficient extension of the survival time of tumor-bearing mice with minimal systemic adverse effects. Meanwhile, the tumors can be monitored in real time by temoporfin-mediated fluorescence imaging and perfluorocarbon (PFC)-microbubble-enhanced ultrasound imaging. Therefore, the nanoengineered neutrophils, i.e., Acouscyte/O2 , are a new type of multifunctional cellular drug, which provides a new platform for the diagnosis and sonodynamic therapy of solid malignant tumors.

Hepatic macrophage targeted siRNA lipid nanoparticles treat non-alcoholic steatohepatitis.

HMGB1 is an inflammatory factor produced by macrophages after liver injury, which plays a key role in promoting NASH progression and further developing into liver fibrosis and cirrhosis. In this study, a mannose-modified HMGB1-siRNA loaded stable nucleic acid lipid particle delivery system (mLNP-siHMGB1) was constructed to target liver macrophages with mannose receptor mediation, thereby silencing HMGB1 protein expression and treating NASH. We also examined the effect of co-administration with docosahexaenoic acid (DHA), a kind of unsaturated fatty acid, on NASH. The results showed that mLNP-siHMGB1 could target macrophages through mannose receptors, effectively silence HMGB1 gene, reduce the release of HMGB1 protein in the liver, regulate liver macrophages to be an anti-inflammatory M2 phenotype, effectively reduce hepatic lobular inflammation and bullous steatosis in the liver, and restore the liver function of NASH model mice to a normal level. After 8 weeks of combined treatment with mLNP-siHMGB1 and DHA, the liver function of NASH model mice recovered rapidly and the hepatic steatosis returned to normal level. In view of inflammation, a key factor in the progression of NASH, we provided an actively targeted siRNA delivery system in this study, and clarified the important role of the delivery system in phenotypic regulation of liver macrophages in NASH. In addition, we also demonstrated the effectiveness of DHA co-administration in NASH treatment. This study provided a useful idea and scientific basis for the development of therapeutic strategies for NASH in the future.

Long-term fertilization modifies the mineralization of soil organic matter in response to added substrate.

The turnover of SOC in soils is strongly influenced by the availability of substrate and nutrients, especially nitrogen (N) and phosphorus (P). Here, we assessed how long-term fertilization modified SOM mineralization in response to added substrate in a tropical forest. We carried out a 90-day incubation study in which we added two structurally similar compounds which differed in microbial metabolic availability: corn cellulose or corn starch to soils collected from a long-term (11 years) factorial N and P fertilization experiment site in a tropical forest in south China. We measured total soil mineralization rate (CO2 efflux) to characterize SOM mineralization and using 13C isotope signatures to determine the source of the CO2 (original soil C or added substrate) and assessed changes in extracellular enzyme activities: acid phosphomonoesterase (AP), ß-1,4-glucosidase (BG), ß-1,4- N-acetaminophen glucosidase (NAG), phenol oxidase (PHO) and peroxidase (PER), and microbial biomarkers to determine whether nutrient stoichiometry and decomposer communities explain differences in SOM mineralization rates. Total C mineralization increased substantially with substrate addition, particularly cellulose (5.38, 7.13, 5.58 and 5.37 times for N, P, NP fertilization and CK, respectively) compared to no substrate addition, and original soil C mineralization was further enhanced in long-term N (3.40% and 5.18% for cellulose and starch addition, respectively) or NP (35.11% for cellulose addition) fertilized soils compared to control treatment. Enzyme activities were stimulated by the addition of both substrates but suppressed by P-fertilization. Addition of both substrates increased microbial investment in P-acquisition, but only starch addition promoted C investment in N-acquisition. Finally, fungal abundance increased with substrate addition to a greater extent than bacterial abundance, particularly in cellulose-amended soils, and the effect was amplified by long-term fertilization. Our findings indicate that SOM mineralization might be enhanced in N and P enrichment ecosystems, since the litter input can liberate microbes from C limitation and stimulate SOM mineralization if N and P are sufficient. Our study further demonstrates that structurally similar substrates can have distinct effects on SOM mineralization and the extent of SOM mineralization is strongly dependent on elemental stoichiometry, as well as the resource requirements of microbial decomposers.

A Photopolymerized Semi-Interpenetrating Polymer Networks-Based Hydrogel Incorporated with Nanoparticle for Local Chemotherapy of Tumors.

PURPOSE: To address the issue of local drug delivery in tumor treatment, a novel nanoparticle-hydrogel superstructure, namely semi-interpenetrating polymer networks (semi-IPNs) hydrogel composed of poly (ethylene glycol) diacrylate (PEGDA) and hyaluronic acid (HA) and incorporated with paclitaxel (PTX) loaded PLGA nanoparticles (PEGDA-HA/PLGA-PTX), was prepared by in situ UV photopolymerization for the use of local drug delivery. METHODS: Using the gelation time, swelling rate and degradation rate as indicators, the optimal proportion of Irgacure 2959 initiator and the concentration of HA was screened and obtained for preparing hydrogels. Next, paclitaxel (PTX) loaded PLGA nanoparticles (PLGA-PTX NPs) were prepared by the emulsion solvent evaporation method. RESULTS: The mass ratio of the initiator was 1%, and the best concentration of HA was 5 mg/mL in PEGDA-HA hydrogel. In vitro experiments showed that PLGA-PTX NPs had similar cytotoxicity to free PTX, and the cell uptake ratio on NCI-H460 cells was up to 96% by laser confocal microscopy and flow cytometry. The drug release of the PEGDA-HA/PLGA-PTX hydrogel local drug delivery system could last for 13 days. In vivo experiments proved that PEGDAHA/PLGA-PTX hydrogel could effectively inhibit the tumor growth without causing toxic effects in mice. CONCLUSIONS: This study demonstrated that the PEGDA-HA/PLGA-PTX hydrogel is a promising local drug delivery system in future clinical applications for tumor therapy. A photopolymerized semi-interpenetrating polymer networks-based hydrogel incorporated with paclitaxel-loaded nanoparticles was fabricated by in situ UV photopolymerization, providing a promised nanoplatform for local chemotherapy of tumors.

ShRNA-mediated silencing of PD-1 augments the efficacy of chimeric antigen receptor T cells on subcutaneous prostate and leukemia xenograft.

Chimeric antigen receptor T cells (CAR-T) immunotherapy has shown promising clinical results in the treatment of leukemia and lymphoma, but the effectiveness is limited for solid tumors. The PD-1/PD-L1 pathway is a key immunosuppressive mechanism for cancer cells to avoid eradication by CAR-T cells. In this study, the shRNA (short hair RNA) gene-silencing technique was used to construct the third-generation of CAR-T cells with PD-1 silencing which targeted CD19 antigen (CD19/△PD-1 CAR-T) and prostate stem cell antigen (PSCA/△PD-1 CAR-T), thereby blocking the PD-1/PD-L1 pathway in treatment of lymphoma and prostate subcutaneous xenograft and enhancing the anti-tumor effect of CAR-T cells. The cell experiments showed that PD-1 silencing in CAR-T cells effectively blocked the PD-1 / PD-L1 pathway. When the ratio of effector to target cell is 8:1, △PD-1 CAR-T cells exhibited higher killing ability and cytokine releasing ability than normal CAR-T cells did. The subcutaneous tumor models were constructed using human chronic myelogenous leukemia cells expressing CD19 (K562-CD19) and human prostate cancer cells expressing PSCA (PC3-PSCA), and treated with CD19/△PD-1 CAR-T and PSCA/△PD-1 CAR-T cells, respectively. The tumor volumes significantly reduced within one week, indicating the good tumor growth inhibitory effect of △PD-1 CAR-T cells. Mice injected with △PD-1 CAR-T cells showed a significantly prolonged survival time compared to those with normal CAR-T cells. This study proved that shRNA-mediated PD-1 silencing technology is an effective strategy for blocking the PD-1/PD-L1 immunosuppression pathway and enhancing the therapeutic effect of CAR-T cells on subcutaneous xenograft. SUMMARY: The effect of CAR-T in treating solid tumors has not been as successful as that in hematological malignancies. The key immunosuppressive mechanism is the expression of PD-1/PD-L1. We used gene silencing technique mediated by shRNA (short hair RNA) to block the PD-1/PD-L1 pathway in lymphoma and prostate tumors, thus enhancing the anti-tumor effect of CAR-T cells on subcutaneous xenograft.

Erythrocyte membrane coated nanoparticle-based control releasing hydrogen sulfide system protects ischemic myocardium.

Aim: To construct a long circulatory and sustained releasing H2S system and explore its protective effects on myocardial ischemia and reperfusion (I/R) injury. Materials & methods: Red blood cell (RBC) membrane-coated, diallyl trisulfide (DATS)-carrying mesoporous iron oxide nanoparticles (MIONs) (RBC-DATS-MIONs) were prepared and characterized. Cytotoxicity and cellular uptake were studied in vitro, followed by in vivo assessment of safety, distribution and effect on cardiac function following I/R injury. Results: RBC-DATS-MIONs exhibited excellent biocompatibility, extended circulatory time and controlled-release of H2S in plasma and myocardium. They exhibited superior therapeutic effects on in vitro hypoxia/reoxygenation models and in vivo myocardial I/R models, which involved various mechanisms, including anti-apoptosis, anti-inflammatory and antioxidant activities. Conclusion: This work provides a new potential platform for best utilizing the protective effects of H2S by prolonging its releasing process.

Surface modified small intestinal submucosa membrane manipulates sequential immunomodulation coupled with enhanced angio- and osteogenesis towards ameliorative guided bone regeneration.

Constructing bioactive guided bone regeneration (GBR) membranes that possess biological multifunctionality is becoming increasingly attractive and promising to meet higher requirements for bone healing. Given the biological responses following implantation, GBR process originates from an early inflammation-driven reaction adjacent to implanted membranes surface. However, to date there is relatively little attention paid to the critical immunoregulatory functions in traditionally designed GBR membranes. Herein, for the first time, we manipulate immunomodulatory properties of the widely-used native small intestinal submucosa (SIS) membrane by incorporating strontium-substituted nanohydroxyapatite coatings and/or IFN-γ to its surface. In vitro results reveal the obtained novel membrane SIS/SrHA/IFN-γ not only promote functions of endothelial cells and osteoblasts directly, but also energetically mediate a sequential M1-M2 macrophages transition to concurrently facilitate angiogenesis and osteogenesis. Moreover, in vivo outcomes of subcutaneous implantation and cranial defects repair further confirm its superior capacity to promote vascularization and in situ bone regeneration than pristine SIS through immunomodulation. These results demonstrate a sequential immunomodulatory strategy renders modified SIS membranes acting as a robust immunomodulator rather than a traditional barrier to significantly ameliorate in vivo GBR outcomes and hence provide important implications that may facilitate concerns on immunomodulatory properties for future GBR developments.