A novel unsaturated polyphosphoester (UPPE) was devised in our previous research, which is a kind of promising scaffold for improving bone regeneration. However, the polymerization process of UPPE scaffolds was unfavorable, which may adversely affect the bioactivity of osteoinductive molecules added if necessary, such as recombinant human bone morphogenetic protein-2 (rhBMP2). The purpose of this study was to build a kind of optimal scaffold named UPPE-PLGA-rhBMP2 (UPB) and to investigate the bioactivity of rhBMP2 in this scaffold. Furthermore, the cytotoxicity and biocompatibility of UPB scaffold was assessed in vitro. A W1/O/W2 method was used to fabricate PLGA-rhBMP2 microspheres, and then the microspheres were added to UPPE for synthesizing UPB scaffold. The morphological characters of PLGA-rhBMP2 microspheres and UPB scaffolds were observed under the scanning electron microscopy and laser scanning confocal microscopy. The cumulative release of UPB scaffolds was detected by using ELISA. The cytotoxicity and biocompatibility of UPB scaffolds were evaluated through examining the adsorption and apoptosis of bone marrow stromal cells (bMSCs) seeded on the surface of UPB scaffolds. The bioactivity of rhBMP2 in UPB scaffolds was assessed through measuring the alkaline phosphates (ALP) activity in bMSCs seeded. The results showed that UPB scaffolds sequentially exhibited burst and sustained release of rhBMP2. The cytotoxicity was greatly reduced when the scaffolds were immersed in buffer solution for 2 h. bMSCs attached and grew on the surface of soaked UPB scaffolds, exerting well biocompatibility. The ALP activity of bMSCs seeded was significantly enhanced, indicating that the bioactivity of rhBMP2 remained and still took effect after the unfavorable polymerization process of scaffolds. It was concluded that UPB scaffolds have low cytotoxicity, good biocompatibility and preserve bioactivity of rhBMP2. UPB scaffolds are promising in improving bone regeneration.

A novel unsaturated polyphosphoester (UPPE) was devised in our previous research, which is a kind of promising scaffold for improving bone regeneration. However, the polymerization process of UPPE scaffolds was unfavorable, which may adversely affect the bioactivity of osteoinductive molecules added if necessary, such as recombinant human bone morphogenetic protein-2 (rhBMP2). The purpose of this study was to build a kind of optimal scaffold named UPPE-PLGA-rhBMP2 (UPB) and to investigate the bioactivity of rhBMP2 in this scaffold. Furthermore, the cytotoxicity and biocompatibility of UPB scaffold was assessed in vitro. A W1/O/W2 method was used to fabricate PLGA-rhBMP2 microspheres, and then the microspheres were added to UPPE for synthesizing UPB scaffold. The morphological characters of PLGA-rhBMP2 microspheres and UPB scaffolds were observed under the scanning electron microscopy and laser scanning confocal microscopy. The cumulative release of UPB scaffolds was detected by using ELISA. The cytotoxicity and biocompatibility of UPB scaffolds were evaluated through examining the adsorption and apoptosis of bone marrow stromal cells (bMSCs) seeded on the surface of UPB scaffolds. The bioactivity of rhBMP2 in UPB scaffolds was assessed through measuring the alkaline phosphates (ALP) activity in bMSCs seeded. The results showed that UPB scaffolds sequentially exhibited burst and sustained release of rhBMP2. The cytotoxicity was greatly reduced when the scaffolds were immersed in buffer solution for 2 h. bMSCs attached and grew on the surface of soaked UPB scaffolds, exerting well biocompatibility. The ALP activity of bMSCs seeded was significantly enhanced, indicating that the bioactivity of rhBMP2 remained and still took effect after the unfavorable polymerization process of scaffolds. It was concluded that UPB scaffolds have low cytotoxicity, good biocompatibility and preserve bioactivity of rhBMP2. UPB scaffolds are promising in improving bone regeneration.
Bone Morphogenetic Protein 2 ; chemistry ; pharmacology ; Bone Regeneration ; drug effects ; Humans ; Lactic Acid ; chemistry ; pharmacology ; Phosphatidylinositol Phosphates ; chemistry ; pharmacology ; Polyglycolic Acid ; chemistry ; pharmacology ; Tissue Scaffolds

Objective To study the biological behaviors and effects of immunoglobulin-like transcript-4 (ILT4) expression in mononuclear cells on the prognosis of sepsis.Methods ILT4 +/+ (WT) and ILT4-knockout mice (ILT4-/-) male BALB/c mice were used for sepsis modeling using cecal ligation puncture (CLP).Flow cytometry was used to measure the levels of expression of ILT4 and major histocompatihility complex class Ⅱ molecules (MHC-Ⅱ) in mononuclear cells of peripheral blood 24 h after CLP.ELISA was used to measure the concentrations of interleukin-6 (IL-6) and serum tumor necrosis factor-alpha (TNF-α) in different groups of mice at 0 h,6 h,12 h,and 24 h after CLP to monitor the survival and prognosis over the course of 168 h.Results ILT4 was highly expressed in mononuclear cells of the peripheral blood of septic mice 24 h after CLP in comparison with that before CLP (1292.00 ± 143.70) vs.(193.50 ± 52.54),P ＜ 0.05.MHC-Ⅱ expression in mononuclear cells of the peripheral blood in ILT4-/-mice was significantly higher than that in WT mice (49.38 ± 5.66)％ vs.(24.25 ± 6.76) ％,P ＜ 0.05).Serum IL-6 was significantly elevated 24 h after CLP compared with that before CLP (470.75 ± 88.03) vs.(54.25 ± 20.04),P ＜ 0.05.The serum IL-6 concentration was much lower in ILT4-/-mice thanthatin MT mice (241.25 ± 45.10)vs.(470.75 ± 88.03),P ＜ 0.05;whereas,there was no significant difference in TNF-α expression between two groups of mice (50.88 ± 6.38) vs.(53.13 ± 5.49),P ＞ 0.05.The survival rate of ILT4-/-mice was significantly higher after CLP compared with WT mice (P ＜ 0.05).Conclusion The high level of ILT4 expression in mononuclear cells were observed in peripheral blood during sepsis and it was found to be associated with high serum IL-6 levels and low MHC-Ⅱ expression in mononuclear cells,leading to increased mortality.