Objective To construct an injectable controlled delivery system of paclitaxel based on thermosensitive PCL1250-PEG1500-PCL1250 hydrogels. Methods A thermosensitive PCL1250-PEG1500-PCL1250 triblock copolymer was synthesized by ring-opening polymerization of e-CL using PEG (Mw=l 500) as the initiator and Sn(Oct)2 as the catalyst. The synthesized PCL1250-PEG1500-PCL1250 copolymers were characterized for their composition,structure, and molecular weight via 1H NMR and GPC techniques. A series of Paclitaxel loaded hydrogels with various predesigned hydrogel concentrations and initial drug loadings were prepared to investigate their gelation ability, in vitro drug release behavior and in vivo biodegradability. Results The results calculated from 1H NMR and GPC indicated that EG/CL ratio(1.55) was consistent with the initial feed ratio(1.6), which offered a strong proof to their composition and molecular structure. The thermosensitive PCL1250-PEG1500-PCL1250 hydrogels exhibited a desirable sol-gel transition ability within the concentration range of 15%-30%. The in vitro release rate of paclitaxel from the paclitaxel/PCL1250-PEG1500-PCL1250 hydrogels was controllable by altering the hydrogel concentrations and initial drug loadings. The PCL1250-PEG1500-PCL1250 hydrogels showed a good in situ gelation ability after subcutaneously injected into mouse back. The in situ formed hydrogels gradually degradated with time and almost disappeared after 45 days in vivo. Conclusion Both the controllable drug release behavior and promising biodegradability of this new thermosensitive PCL1250-PEG1500-PCL1250 hydrogels paved a way to develop a novel delivery system for paclitaxel.

Objective:To investigate the distribution rules of artemisia pollen and the clinical sensitization characteristics of allergic rhinitis (AR) induced by artemisia pollen in three urban and rural areas of Inner Mongolia.Methods:From March to October 2019, in 3 central cities (Chifeng, Hohhot, Ordos) and rural areas of Inner Mongolia, an epidemiological investigation method combining multi-stage stratified random sampling and face-to-face questionnaire survey was adopted to screen suspected AR patients, and skin prick test (SPT) was applied for diagnosis. At the same time, pollen monitoring was carried out in 3 areas to analyze the distribution and clinical sensitization characteristics of artemisia pollen.SPSS26.0 statistical software was used to process all the data. Chi-square test was used to compare rates among different age, sex, region and nationality, Spearman test was used to describe correlation analysis, and pairwise comparison of positive rates among multiple samples was used Bonferroni method.Results:Among the 6 393 subjects, 1 093 cases were diagnosed with AR, and the prevalence of AR was 17.10% (1 093/6 393). Among them, pollen-induced allergic rhinitis, the prevalence of PiAR was 10.97% (701/6 393), accounting for 64.14%(701/1 093).The highest incidence was in the youth group (20-39 years old), accounting for 46.94% (329/701).The diagnosed prevalence was higher in females than in males (11.35% vs. 10.64%, χ2 value 12.304, P<0.001).The prevalence rate of ethnic minority was higher than that of Han nationality (13.01% vs. 10.65%, χ2 value 6.296, P=0.008).The prevalence in urban areas was also significantly higher than that in rural areas (18.40% vs. 5.50%, χ2 value 10.497, P<0.001).There was significant difference in prevalence rate among the three regions in Inner Mongolia (6.06% in Chifeng, 13.46% in Hohhot, 16.39% in Ordos, χ2 value 70.054, P<0.001).The main clinical symptoms of artemisia PiAR were sneezing (95.58%), nasal congestion (91.73%) and nasal itching (89.30%).Allergic conjunctivitis accounted for 79.60% (558/701), chronic sinusitis for 55.63% (390/701), asthma for 23.25% (163/701).The pattern of artemisia pollen sensitization was mainly multiple sensitization, and the frequency of clinical symptoms and clinical diseases induced by hypersensitization with other allergens accounted for more than that caused by single artemisia pollen. The spread period of Artemisia pollen in the three regions was from June to October, and the peak state was in August in summer. The peak time of clinical symptoms in artemisia PiAR patients was about 2 weeks earlier than the peak time of pollen concentration, and the two were significantly positively correlated ( R=0.7671, P<0.001). Conclusion:Artemisia pollens are the dominant pollens in late summer and early autumn in Inner Mongolia, and the prevalence of artemisia PiAR is high. Controlling the spread of Artemisia pollens is of great significance for the prevention and treatment of AR.

Objective:To investigate the distribution rules of artemisia pollen and the clinical sensitization characteristics of allergic rhinitis (AR) induced by artemisia pollen in three urban and rural areas of Inner Mongolia.Methods:From March to October 2019, in 3 central cities (Chifeng, Hohhot, Ordos) and rural areas of Inner Mongolia, an epidemiological investigation method combining multi-stage stratified random sampling and face-to-face questionnaire survey was adopted to screen suspected AR patients, and skin prick test (SPT) was applied for diagnosis. At the same time, pollen monitoring was carried out in 3 areas to analyze the distribution and clinical sensitization characteristics of artemisia pollen.SPSS26.0 statistical software was used to process all the data. Chi-square test was used to compare rates among different age, sex, region and nationality, Spearman test was used to describe correlation analysis, and pairwise comparison of positive rates among multiple samples was used Bonferroni method.Results:Among the 6 393 subjects, 1 093 cases were diagnosed with AR, and the prevalence of AR was 17.10% (1 093/6 393). Among them, pollen-induced allergic rhinitis, the prevalence of PiAR was 10.97% (701/6 393), accounting for 64.14%(701/1 093).The highest incidence was in the youth group (20-39 years old), accounting for 46.94% (329/701).The diagnosed prevalence was higher in females than in males (11.35% vs. 10.64%, χ2 value 12.304, P<0.001).The prevalence rate of ethnic minority was higher than that of Han nationality (13.01% vs. 10.65%, χ2 value 6.296, P=0.008).The prevalence in urban areas was also significantly higher than that in rural areas (18.40% vs. 5.50%, χ2 value 10.497, P<0.001).There was significant difference in prevalence rate among the three regions in Inner Mongolia (6.06% in Chifeng, 13.46% in Hohhot, 16.39% in Ordos, χ2 value 70.054, P<0.001).The main clinical symptoms of artemisia PiAR were sneezing (95.58%), nasal congestion (91.73%) and nasal itching (89.30%).Allergic conjunctivitis accounted for 79.60% (558/701), chronic sinusitis for 55.63% (390/701), asthma for 23.25% (163/701).The pattern of artemisia pollen sensitization was mainly multiple sensitization, and the frequency of clinical symptoms and clinical diseases induced by hypersensitization with other allergens accounted for more than that caused by single artemisia pollen. The spread period of Artemisia pollen in the three regions was from June to October, and the peak state was in August in summer. The peak time of clinical symptoms in artemisia PiAR patients was about 2 weeks earlier than the peak time of pollen concentration, and the two were significantly positively correlated ( R=0.7671, P<0.001). Conclusion:Artemisia pollens are the dominant pollens in late summer and early autumn in Inner Mongolia, and the prevalence of artemisia PiAR is high. Controlling the spread of Artemisia pollens is of great significance for the prevention and treatment of AR.