Bio-functional hydroxyapatite-coated 3D porous polyetherketoneketone scaffold for enhanced osteogenesis and osteointegration in orthopedic applications.

Polyetherketoneketone (PEKK), a high-performance thermoplastic special engineering material, maintains bone-like mechanical properties and has received considerable attention in the biomedical field. The 3D printing technique enables the production of porous scaffolds with a honeycomb structure featuring precisely controlled pore size, porosity and interconnectivity, which holds significant potential for applications in tissue engineering. The ideal pore architecture of porous PEKK scaffolds has yet to be elucidated. Porous PEKK scaffolds with five pore sizes P200 (225 ± 9.8 µm), P400 (411 ± 22.1 µm), P600 (596 ± 23.4 µm), P800 (786 ± 24.2 µm) and P1000 (993 ± 26.0 µm) were produced by a 3D printer. Subsequently, the optimum pore size, the P600, for mechanical properties and osteogenesis was selected based on in vitro experiments. To improve the interfacial bioactivity of porous PEKK scaffolds, hydroxyapatite (HAp) crystals were generated via in situ biomimetic mineralization induced by the phase-transited lysozyme coating. Herein, a micro/nanostructured surface showing HAp crystals on PEKK scaffold was developed. In vitro and in vivo experiments confirmed that the porous PEKK-HAp scaffolds exhibited highly interconnected pores and functional surface structures that were favorable for biocompatibility and osteoinductivity, which boosted bone regeneration. Therefore, this work not only demonstrates that the pore structure of the P600 scaffold is suitable for PEKK orthopedic implants but also sheds light on a synergistic approach involving 3D printing and biomimetic mineralization, which has the potential to yield customized 3D PEKK-HAp scaffolds with enhanced osteoinductivity and osteogenesis, offering a promising strategy for bone tissue engineering.

Omega-3 Polyunsaturated Fatty Acids Alleviate Intestinal Barrier Dysfunction in Obstructive Jaundice Rats.

Obstructive jaundice (OJ) can cause multiple pathophysiological consequences including intestinal barrier dysfunction. Omega-3 has been indicated to have a promising therapeutic effect on OJ. This study aimed to further investigate the functions of omega-3 on OJ-induced intestinal injury. A rat OJ model was established by bile duct ligation with or without omega-3 administration. ELISA was utilized for measuring serum levels of inflammatory cytokines. Hematoxylin-eosin staining and TUNEL staining were employed for detecting the morphological changes and cell apoptosis in rat intestine. Western blotting was utilized for evaluating expression of tight junction proteins in the intestinal tissues. Omgea-3 offset the reduction in body weight of OJ rats. Omega-3 alleviated inflammatory response, pathological damages and cell apoptosis in the intestine of OJ rats. Additionally, omega-3 enhanced levels of tight junction proteins in the intestinal tissues of OJ rats. Omega-3 ameliorates OJ-triggered impairment of intestinal barrier function in rats.

Synthesis of acidified magnetic sludge-biochar and its role in ammonium nitrogen removal: Perception on effect and mechanism.

An acidified magnetic sludge-biochar (MSB) was prepared to enhance ammonium nitrogen (AN) removal efficiency in eutrophic water, and MSB was obtained by secondary pyrolysis of sludge biochar powder. A series of MSB were prepared under 300, 400, 500, 600 °C and different valence states of iron ions by impregnation pyrolysis, which is based on the deposition of unstable iron minerals on biochar matrix. Physicochemical properties of pristine biochar and MSB were revealed through characterization analysis, suggesting that MSB prepared by ferric chloride at 400 °C presented the largest adsorption capacity, and the acid-modification enhanced the ammonium adsorption capacity by 10.7%. Electrostatic attraction and ion-exchange processes were identified as the main adsorption mechanisms of MSB on AN. As the most dominant mechanism, ion exchange of AN with functional groups containing -OH and CO on the surface of MSB resulted in the relative content of -OH (61.3%) and CO (11.5%) bonds reduced to 34.2% and 7.0% respectively. The novel magnetic sludge-biochar with acid-modification possessed enhanced electron transfer capacity, revealing a removal pathway of ammonium by nitrification. The findings above demonstrated that MSB is a promising adsorbent for ammonium removal and can be applied to the natural nitrogen-rich water regulation.

[Surveillance of schistosomiasis in Sichuan Province, 2005-2010].

OBJECTIVE: To understand the epidemic trend of schistosomiasis in Sichuan Province so as to provide the evidence for formulating schistosomiasis control strategy. METHODS: According to the National Schistosomiasis Surveillance Protocol, the national surveillance sites in Sichuan Province were selected. The schistosomiasis surveillance was carried out continuously from 2005 to 2010. RESULTS: Nine national schistosomiasis surveillance sites were established in Pujiang, Guanghan, Zhongjiang, Fucheng, Dongpo, Danling, Renshou, Xichang and Dechang counties. The Oncomelania hupensis snail area decreased from 351 853 m2 in 2005 to 128 285 m2 in 2010, the snail density from 0.70 to 0.21 per 0.1 m2, the snail infection rate from 0.06% to 0, the positive rate of human serum schistosome antibody from 19.41% to 7.62%, the schistosome infection rate of human population from 1.93% to 0.10%, and the infection rate of livestock from 4.50% to 1.02%. The snails were found mainly in ditch, rice field and other moist field. CONCLUSIONS: Though the endemic of schistosomiasis has reached a low level in Sichuan Province, the endemic situation fluctuates at a narrow range in some surveillance sites. Therefore, the surveillance work should be carried out continuously.

[Study on the re-emerging situation of schistosomiasis epidemics in areas already under control and interruption].

OBJECTIVE: To study the current situation and the cause of schistosomiasis resurgence in order to provide reference for formulation of control strategy. METHODS: Data in 1999 - 2003 and baseline data in some areas were collected and analyzed retrospectively. RESULTS: Resurgence was seen in 6.15% (16/260) of the areas and one farm where transmission of schistosomiasis had been interrupted and 33.33% (21/64) of the areas already under control. Snails appeared to have been rebounded only in six counties (farm) while in thirty two counties that rebound was seen in both snails and disease prevalence. Tendency of increase in the total numbers of patients, acute patients and cattle with schistosomiasis, areas with snails were seen from 1999 to 2003. CONCLUSIONS: Environmental, ecological, societal factors such as flood, acequia, lack of expenditure and lack of incentives at work etc. contributed to the resurgence of epidemics in those areas that criteria had been reached. Surveillance and supervision on the sources of infection and snail diffusion, especially in the areas where the transmission of schistosomiasis had already been under control.