Effect of different carboxylic acids in cyclodextrin functionalization of cellulose nanocrystals for prolonged release of carvacrol.

Current investigations deal with new surface functionalization strategy of nanocrystalline cellulose-based substrates to impart active molecule release properties. In this study, cellulose nanocrystals (CNC) were surface-functionalized with ß-cyclodextrin (ß-CD) using succinic acid (SA) and fumaric acid (FA) as bridging agents. The main objective of this surface modification performed only in aqueous media was to obtain new active materials able to release antibacterial molecules over a prolonged period of time. The reactions were conducted by immersing the CNC film into a solution composed of ß-CD, SA and FA, leading to CNC grafting. The materials were characterized by infrared spectroscopy (FT-IR), Quartz crystal microbalance-dissipation (QCM-D), AFM and phenolphthalein (PhP) was used to determine the efficiency of CNC grafting with ß-CD. The results indicated that ß-CD was successfully attached to the CNC backbone through the formation of ester bonds. Furthermore, carvacrol was entrapped by the attached ß-CD and a prolonged release was confirmed. In particular, CNC grafted to ß-CD in the presence of FA was selected as the best solution. The antibacterial activity and the controlled release were studied for this sample. Considerably longer bacterial activity against B. subtilis was observed for CNC grafted to ß-CD compared to CNC and CNC-FA, confirming the promising impact of the present strategy.

Yersinia-triggered arthritis in IL-12p40-deficient mice: relevant antigens and local expression of Toll-like receptor mRNA.

OBJECTIVES: To study the role of IL-12p40 at the onset of reactive arthritis (ReA) after Yersinia enterocolitica O:3 infection, and analyse relevant microbial antigens and articular expression of Toll-like receptor (TLR) mRNA. METHODS: Wild-type C57BL/6 and IL-12p40-deficient (IL-12p40-/-) mice were orogastrically infected with Y. enterocolitica O:3. Early (day 3) and late (day 21) after infection, the number of bacteria were determined in Peyer's patches (PP), mesenteric lymph nodes (MLN), the spleen, and joints. Histological studies of joints were performed. Collagen-specific and anti-Yersinia antibodies were measured by enzyme-linked immunosorbent assay (ELISA). The presence of Yersinia antigens was studied by dot blot. Induction of articular mRNA of TLR2, TLR4, and tumour necrosis factor (TNF)-alpha was analysed by reverse transcription-polymerase chain reaction (RT-PCR). TNFalpha protein levels were measured by ELISA. RESULTS: At day 3, bacterial recovery in PP, MLN, and spleen was significantly increased in IL-12p40-/- mice. Histopathological changes were observed in IL-12p40-/- mice at day 21 after infection, and correlated with higher antibody response against type II collagen. Although live bacteria could not be isolated at day 21 after infection, articular microbial components, especially from the outer membrane (OM), were detected. Moreover, intra-articular immunoglobulins to Yersinia antigens were significantly higher in IL-12p40-/- mice. Furthermore, mRNA levels for TLR2, TLR4 and TNFalpha, and TNFalpha protein were increased in joints from IL-12p40-/- mice. CONCLUSIONS: We concluded that IL-12p40 influences the resistance against Yersinia-triggered ReA. Bacterial products such as Yersinia OM could contribute to the ReA by induction of articular TLR expression, which results in an inflammatory response in the joint.

Low-energy laser therapy for prevention of oral mucositis in hematopoietic stem cell transplantation.

AIM: To evaluate the clinical effects of laser therapy on the prevention and reduction of oral mucositis in patients who underwent hematopoietic stem cell transplantation (HSCT). PATIENTS AND METHODS: From January 2003 to September 2004, 24 patients received prophylactic laser therapy (L+ group). The applications started from the beginning of the conditioning regimen up to day +2. The oral assessment was performed daily until day +30. This group was compared with historical controls, namely 25 patients, who did not receive laser therapy (L- group). RESULTS: All patients developed some grade of mucositis. However, the L- group presented initial mucositis by 4.36 days, whereas the L+ group presented it in 6.12 days (P = 0.01). The maximum mucositis occurred between day +2 and day +6 with healing by day +25 in the L- group and between day +2 and day +7 with healing by day +14 for the L+ group (P = 0.84). Laser therapy also reduced the time of oral pain from 5.64 to 2.45 days (P = 0.04), and decreased the consumption of morphine (P = 0.07). CONCLUSION: This study suggests that laser therapy can be useful in oral mucositis to HSCT patients and improve the patient's quality of life. However, controlled randomized trials should be performed to confirm the real efficacy of laser therapy.