Calcium phosphate with well controlled nanostructure for tissue engineering

Dongliang Jiang,Jingxian Zhang 한국물리학회 2009 Current Applied Physics Vol.9 No.3

Calcium phosphates comprise a large family of compounds with important biological applications, including osteologic implant coatings, grafts, scaffolds and bone cavity fillings, and vehicles for drug, protein and gene delivery, due to its similarity with the mineral constituents of human bones and teeth. Properties of calcium phosphate, including bioactivity, biocompatibility, solubility, mechanical properties and absorption can be tailored over wide ranges by controlling the particle composition, size, morphology and assembly. For these reasons, it is of great importance to develop synthesis methods focused on the precise control of particle size, morphology, and chemical composition. Herein, we present our approaches related with calcium phosphate with careful size and structural control through template guided process. First, HA nanorods were prepared through hydrothermal method. Phosphate ester was used as the structure directing agent. After hydrothermal treatment, calcium phosphate rods were obtained with well controlled particle size and porosity. Second, sodium salt carboxymethyl cellulose (CMC) was used as the template to guide the formation and assembly of HA nanoparticles. The composites contain nanosized hydroxyapatite with structural features close to those of biological apatites. These composites with special structural features might be attractive for bone tissue engineering applications. Calcium phosphates comprise a large family of compounds with important biological applications, including osteologic implant coatings, grafts, scaffolds and bone cavity fillings, and vehicles for drug, protein and gene delivery, due to its similarity with the mineral constituents of human bones and teeth. Properties of calcium phosphate, including bioactivity, biocompatibility, solubility, mechanical properties and absorption can be tailored over wide ranges by controlling the particle composition, size, morphology and assembly. For these reasons, it is of great importance to develop synthesis methods focused on the precise control of particle size, morphology, and chemical composition. Herein, we present our approaches related with calcium phosphate with careful size and structural control through template guided process. First, HA nanorods were prepared through hydrothermal method. Phosphate ester was used as the structure directing agent. After hydrothermal treatment, calcium phosphate rods were obtained with well controlled particle size and porosity. Second, sodium salt carboxymethyl cellulose (CMC) was used as the template to guide the formation and assembly of HA nanoparticles. The composites contain nanosized hydroxyapatite with structural features close to those of biological apatites. These composites with special structural features might be attractive for bone tissue engineering applications.

Robust Hybrid Controller Design for Batch Processes with Time Delay and Its Application in Industrial Processes

Weiyan Yu,Jiang Song,Jingxian Yu 제어·로봇·시스템학회 2019 International Journal of Control, Automation, and Vol.17 No.11

A new design method of two-dimensional (2D) controller for multi-phase batch processes with time delay and disturbances is proposed to ensure the stability of the control system and realize efficient production in industry. The batch process is first converted to an equivalent but different dimensional 2D-FM switched system. Based on the 2D system framework, then sufficient conditions of a controller existence expressed by linear matrix inequalities (LMIs) that stabilizing system is given by means of the average dwell time method. Meanwhile, robust hybrid 2D controller design containing extended information is proposed and the minimum runtime lower bound of each sub-system is accurately calculated. The design advantages of the controller depend on the size of the time delay so it has a certain degree of robustness. At the same time, considering the exponential stability, the system can have a faster rate of convergence. In addition, the introduction of extended information has improved the control performance of the system to some extent. The acquisition of minimum time at different phases will promote certain production efficiency and thus reduce energy consumption. Finally, an injection process in industrial production process has been taken as an example to verify effectiveness of the proposed method.

A multifunctional lactic acid based plasticizer used for plasticizing PVC and PLA: Endowing PLA elastic restore capability

Minjia Lu,Pingping Jiang,Pingbo Zhang,Shan Feng,Zhixuan Cui,Qingkui Song,Yong Zhao,Jingxian Shen,Yiyi Fan,Huixian Lu 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.128 No.-

A novel multifunctional plasticizer, cyclohexyl triethylene glycol oligo-lactate (CTLE) was designed by atwo-step esterification reaction using green non-toxic biomass lactic acid as raw material. Its structurewas characterized by 1H NMR, FT-IR and TOF-MS. Thermogravimetric analysis (TGA), tensile test andleaching test were used to evaluate the plasticizer effect of PVC or PLA blends. Compared with commercialplasticizers, CTLE showed more outstanding thermal stability, flexibility and migration stability. Under the same condition with the addition of 50 phr plasticizer, the CTLE plasticized PVC film hadthe lowest glass transition temperature (TgCTLE-50 = 24.6 C) and the highest initial decomposition temperature(TiCTLE-50 = 265.4 C). In PLA blends, only the CTLE plasticized PLA film could recover after fracture,and the stress relaxation test results showed that the stress value of PLA-CTLE-20 drops sharply to anon-zero value, showing elastic characteristics. We estimate that the excellent plasticity of CTLE is due toits molecular structure. Among them, a large number of polar groups form intermolecular forces withPVC chain segments to make the binding tight, and the ring structure increases the free volume betweenPVC chain segments.

LincR-PPP2R5C Promotes Th2 Cell Differentiation Through PPP2R5C/PP2A by Forming an RNA–DNA Triplex in Allergic Asthma

Ji Ningfei,Chen Zhongqi,Wang Zhengxia,Sun Wei,Yuan Qi,Zhang Xijie,Jia Xinyu,Wu Jingjing,Jiang Jingxian,Song Meijuan,Xu Tingting,Liu Yanan,Ma Qiyun,Sun Zhixiao,Bao Yanmin,Zhang Mingshun,Huang Mao 대한천식알레르기학회 2024 Allergy, Asthma & Immunology Research Vol.16 No.1

Purpose: The roles and mechanisms of long noncoding RNAs (lncRNAs) in T helper 2 (Th2) differentiation from allergic asthma are poorly understood. We aimed to explore a novel lncRNA, LincR-protein phosphatase 2 regulatory subunit B' gamma (PPP2R5C), in Th2 differentiation in a mouse model of asthma. Methods: LincR-PPP2R5C from RNA-seq data of CD4+ T cells of asthma-like mice were validated and confirmed by quantitative reverse transcription polymerase chain reaction, northern blotting, nuclear and cytoplasmic separation, and fluorescence in situ hybridization (FISH). Lentiviruses encoding LincR-PPP2R5C or shRNA were used to overexpress or silence LincR-PPP2R5C in CD4+ T cells. The interactions between LincR-PPP2R5C and PPP2R5C were explored with western blotting, chromatin isolation by RNA purification assay, and fluorescence resonance energy transfer. An ovalbumin-induced acute asthma model in knockout (KO) mice (LincR-PPP2R5C KO, CD4 conditional LincR-PPP2R5C KO) was established to explore the roles of LincR-PPP2R5C in Th2 differentiation. Results: LncR-PPP2R5C was significantly higher in CD4+ T cells from asthmatic mice ex vivo and Th2 cells in vitro. The lentivirus encoding LincR-PPP2R5C suppressed Th1 differentiation; in contrast, the short hairpin RNA (shRNA) lentivirus decreased LincR-PPP2R5C and Th2 differentiation. Mechanistically, LincR-PPP2R5C deficiency suppressed the phosphatase activity of the protein phosphatase 2A (PP2A) holocomplex, resulting in a decline in Th2 differentiation. The formation of an RNA-DNA triplex between LincR-PPP2R5C and the PPP2R5C promoter enhanced PPP2R5C expression and activated PP2A. LincR-PPP2R5C KO and CD4 conditional KO decreased Th2 differentiation, airway hyperresponsiveness and inflammatory responses. Conclusions: LincR-PPP2R5C regulated PPP2R5C expression and PP2A activity by forming an RNA-DNA triplex with the PPP2R5C promoter, leading to Th2 polarization in a mouse model of acute asthma. Our data presented the first definitive evidence of lncRNAs in the regulation of Th2 cells in asthma.