BACKGROUND: Periodontitis is a severe chronic inflammatory disease, whose traditional systemic antimicrobial therapy faces great limitations. In-situ gels provide an effective solution as an emerging local drug delivery system. METHODS: In this study, the novel thermosensitive poloxamer/carbopol in-situ gels loaded with 20 lmol/L quercetin for the treatment of periodontitis were prepared by cold method. Thirteen batches of in-situ gels based on two independent factors (X1 : poloxamer 407 and X2 : carbopol 934P) were designed and optimized by the statistical method of central composite design (CCD). The transparency, pH, injectability, viscosity, gelation temperature, gelation time, elasticity modulus, degradation rate and in-vitro drug release studies of the batches were evaluated, and the percentage of drug release in the first hour, the time required for 90% drug release, gelation temperature, and gelation time were selected as dependent variables. RESULTS: These two independent factors significantly affected the four dependent variables (p < 0.05). The optimization result displayed that the optimized concentration of poloxamer 407 was 20.84% (w/v), and carbopol 934P was 0.5% (w/v). The optimized formulation showed a clear appearance (++), acceptable injectability (Pass), viscosity(151,798 mPa s), gelation temperature (36 °C), gelation time (213 s), preferable cell viability and cell proliferation, conformed to first-order release kinetics, and had a significant antibacterial effect. CONCLUSIONS The article demonstrates the great potential of the quercetin in-situ gel as an effective treatment for periodontitis.

BACKGROUND: Periodontitis is a severe chronic inflammatory disease, whose traditional systemic antimicrobial therapy faces great limitations. In-situ gels provide an effective solution as an emerging local drug delivery system. METHODS: In this study, the novel thermosensitive poloxamer/carbopol in-situ gels loaded with 20 lmol/L quercetin for the treatment of periodontitis were prepared by cold method. Thirteen batches of in-situ gels based on two independent factors (X1 : poloxamer 407 and X2 : carbopol 934P) were designed and optimized by the statistical method of central composite design (CCD). The transparency, pH, injectability, viscosity, gelation temperature, gelation time, elasticity modulus, degradation rate and in-vitro drug release studies of the batches were evaluated, and the percentage of drug release in the first hour, the time required for 90% drug release, gelation temperature, and gelation time were selected as dependent variables. RESULTS: These two independent factors significantly affected the four dependent variables (p < 0.05). The optimization result displayed that the optimized concentration of poloxamer 407 was 20.84% (w/v), and carbopol 934P was 0.5% (w/v). The optimized formulation showed a clear appearance (++), acceptable injectability (Pass), viscosity(151,798 mPa s), gelation temperature (36 °C), gelation time (213 s), preferable cell viability and cell proliferation, conformed to first-order release kinetics, and had a significant antibacterial effect. CONCLUSIONS The article demonstrates the great potential of the quercetin in-situ gel as an effective treatment for periodontitis.

BACKGROUND: Periodontitis is a severe chronic inflammatory disease, whose traditional systemic antimicrobial therapy faces great limitations. In-situ gels provide an effective solution as an emerging local drug delivery system. METHODS: In this study, the novel thermosensitive poloxamer/carbopol in-situ gels loaded with 20 lmol/L quercetin for the treatment of periodontitis were prepared by cold method. Thirteen batches of in-situ gels based on two independent factors (X1 : poloxamer 407 and X2 : carbopol 934P) were designed and optimized by the statistical method of central composite design (CCD). The transparency, pH, injectability, viscosity, gelation temperature, gelation time, elasticity modulus, degradation rate and in-vitro drug release studies of the batches were evaluated, and the percentage of drug release in the first hour, the time required for 90% drug release, gelation temperature, and gelation time were selected as dependent variables. RESULTS: These two independent factors significantly affected the four dependent variables (p < 0.05). The optimization result displayed that the optimized concentration of poloxamer 407 was 20.84% (w/v), and carbopol 934P was 0.5% (w/v). The optimized formulation showed a clear appearance (++), acceptable injectability (Pass), viscosity(151,798 mPa s), gelation temperature (36 °C), gelation time (213 s), preferable cell viability and cell proliferation, conformed to first-order release kinetics, and had a significant antibacterial effect. CONCLUSIONS The article demonstrates the great potential of the quercetin in-situ gel as an effective treatment for periodontitis.

BACKGROUND: Periodontitis is a severe chronic inflammatory disease, whose traditional systemic antimicrobial therapy faces great limitations. In-situ gels provide an effective solution as an emerging local drug delivery system. METHODS: In this study, the novel thermosensitive poloxamer/carbopol in-situ gels loaded with 20 lmol/L quercetin for the treatment of periodontitis were prepared by cold method. Thirteen batches of in-situ gels based on two independent factors (X1 : poloxamer 407 and X2 : carbopol 934P) were designed and optimized by the statistical method of central composite design (CCD). The transparency, pH, injectability, viscosity, gelation temperature, gelation time, elasticity modulus, degradation rate and in-vitro drug release studies of the batches were evaluated, and the percentage of drug release in the first hour, the time required for 90% drug release, gelation temperature, and gelation time were selected as dependent variables. RESULTS: These two independent factors significantly affected the four dependent variables (p < 0.05). The optimization result displayed that the optimized concentration of poloxamer 407 was 20.84% (w/v), and carbopol 934P was 0.5% (w/v). The optimized formulation showed a clear appearance (++), acceptable injectability (Pass), viscosity(151,798 mPa s), gelation temperature (36 °C), gelation time (213 s), preferable cell viability and cell proliferation, conformed to first-order release kinetics, and had a significant antibacterial effect. CONCLUSIONS The article demonstrates the great potential of the quercetin in-situ gel as an effective treatment for periodontitis.

BACKGROUND: Periodontitis is a severe chronic inflammatory disease, whose traditional systemic antimicrobial therapy faces great limitations. In-situ gels provide an effective solution as an emerging local drug delivery system. METHODS: In this study, the novel thermosensitive poloxamer/carbopol in-situ gels loaded with 20 lmol/L quercetin for the treatment of periodontitis were prepared by cold method. Thirteen batches of in-situ gels based on two independent factors (X1 : poloxamer 407 and X2 : carbopol 934P) were designed and optimized by the statistical method of central composite design (CCD). The transparency, pH, injectability, viscosity, gelation temperature, gelation time, elasticity modulus, degradation rate and in-vitro drug release studies of the batches were evaluated, and the percentage of drug release in the first hour, the time required for 90% drug release, gelation temperature, and gelation time were selected as dependent variables. RESULTS: These two independent factors significantly affected the four dependent variables (p < 0.05). The optimization result displayed that the optimized concentration of poloxamer 407 was 20.84% (w/v), and carbopol 934P was 0.5% (w/v). The optimized formulation showed a clear appearance (++), acceptable injectability (Pass), viscosity(151,798 mPa s), gelation temperature (36 °C), gelation time (213 s), preferable cell viability and cell proliferation, conformed to first-order release kinetics, and had a significant antibacterial effect. CONCLUSIONS The article demonstrates the great potential of the quercetin in-situ gel as an effective treatment for periodontitis.

Objective::A multi-organ chip of intestine-liver-breast cancer was constructed based on microfluidic technology and used for pharmacokinetics-pharmacodynamics (PK-PD) study of drugs in vitro. Method::A multi-organ chip comprising a 4-layer polydimethylsiloxane (PDMS) substrate and a 2-layer poly(methyl methacrylate) (PMMA) cover was constructed by microfluidic technology. The connection between cells was investigated by staining the 21-day-grown human colon cancer cell line Caco-2 cell layer and the 3-day-grown human umbilical vein endothelial cell line HUVEC cell layer with CellTracker Red/Green and Hoechst, respectively. The transmission rates of 2 g·L^-1 fluorescein sodium and 33.28 mg·L^-1 propranolol acrossing the cell layer were employed to verify the function of the constructed intestinal module. The metabolic level of the liver module was investigated by comparing the inhibition rate of 125 μmol·L^-1 cyclophosphamide against human breast cancer cell line MCF-7 cells treated with human hepatoma cell line HepG2 cells in a conventional well plate and chip liver module for 48 h. The secretion of albumin by HepG2 cells in the chip was detected to verify the synthesis function of hepatic module. Caco-2 cell layer, HUVEC cell layer, HepG2 cell layer, MCF-7 cell layer and dialysis membrane were assembled on the chip, the culture medium containing 55 mg·L^-1 propranolol was injected into the upper channel of the chip for 4 h, and then changed into the normal culture solution. The mass concentration of propranolol in the lower circulating culture medium at each time point within 72 h was determined, and the drug-time curve was drawn. The culture medium containing 125 μmol·L^-1 cyclophosphamide, 5 μmol·L^-1 paclitaxel, 50 μmol·L^-1 capecitabine was injected into the circulating fluid in the upper layer of the chip, in order to study the inhibition rates of the three anti-tumor drugs on the MCF-7 cell layer on the chip within 72 h, and the results were compared with those of the 96-well plate. Result::The constructed chip performed well. The Caco-2 and HUVEC cell layers were tightly connected. The transmission of fluorescein sodium and propranolol between the cell layers demonstrated that the constructed intestinal module had good absorption and transport function. The inhibition rate of MCF-7 by 125 μmol·L^-1 cyclophosphamide after metabolism of HepG2 cells on the well plate was 22.12%, and the inhibition rate of MCF-7 by the unmetabolized cyclophosphamide was 1.84%. The inhibition rate of MCF-7 increased to 32.13%after injected 125 μmol·L^-1 cyclophosphamide from the upper layer of the chip liver module, and the inhibition rate of MCF-7 after injection from the lower layer of the chip liver module was 7.23%. The mass concentration of propranolol on the chip changed with time, which was basically consistent with that in vivo. The inhibition rate of MCF-7 on the plate with 125 μmol·L^-1 cyclophosphamide was lower than that on the chip, and the inhibition rates of MCF-7 on the plate with 5 μmol·L^-1 paclitaxel and 50 μmol·L^-1 capecitabine were higher than those on the chip. Conclusion::The constructed multi-organ chip of intestine-liver-breast cancer has the absorption and transport function of the intestine and the metabolic function of the liver. The chip can reflect the pharmacokinetic properties of propranolol in vivo, and can be used for pharmacodynamic studies of paclitaxel and capecitabine.