ABSTRACT
We aimed to investigate the effects of calcium-ammonium nitrate (CAN) fed to lactating dairy goats on dry matter (DM) intake, digestibility of nutrients, milk properties (composition, antioxidant capacity, fatty acid profile, and nitrate residues), and ruminal fermentation parameters. Twelve lactating Saanen goats averaging 98.5 ± 13.1 days in milk, 53.5 ± 3.3 kg of body weight, and 2.53 ± 0.34 kg of milk/day were randomly assigned in four 3 × 3 Latin squares to receive the following diets: a control group (without CAN) with 7.3 g/kg DM of urea (URE), 10 g/kg DM of CAN (CAN10), and 20 g/kg DM of CAN (CAN20). Each period lasted 21 days, with 14 days for diet adaptation and seven days for data and sample collection. The DM intake, digestibility of nutrients, yields of milk, 3.5% fat-corrected milk, and energy-corrected milk were not affected by treatments. Similarly, there were no treatment effects on the yields and concentrations of milk fat, true protein, and lactose, along with minor effects on milk fatty acid profile. Total antioxidant capacity in milk was unaffected by treatments; however, concentration of conjugated dienes increased, while thiobarbituric acid reactive substances in milk decreased linearly. Nitrate and nitrite residues in milk were elevated by treatments, while the total of volatile fatty acids and ammonia-N concentration in the rumen were unaffected. Collectively, feeding CAN (up to 20 g/kg of DM) to lactating dairy goats did not affect feed intake, nutrient digestibility, and milk composition; however, it may increase milk lipid oxidation, as evidenced by increased conjugated diene concentration.
ABSTRACT
Phthalocyanine aluminum chloride (Pc) is a clinically viable photosensitizer (PS) to treat skin lesions worsened by microbial infections. However, this molecule presents a high self-aggregation tendency in the biological fluid, which is an in vivo direct administration obstacle. This study proposed the use of bioadhesive and thermoresponsive hydrogels comprising triblock-type Pluronic F127 and Carbopol 934P (FCarb) as drug delivery platforms of Pc (FCarbPc)-targeting topical administration. Carbopol 934P was used to increase the F127 hydrogel adhesion on the skin. Rheological analyses showed that the Pc presented a low effect on the hydrogel matrix, changing the gelation temperature from 27.2 ± 0.1 to 28.5 ± 0.9 °C once the Pc concentration increases from zero to 1 mmol L-1. The dermatological platform showed matrix erosion effects with the release of loaded Pc micelles. The permeation studies showed the excellent potential of the FCarb platform, which allowed the partition of the PS into deeper layers of the skin. The applicability of this dermatological platform in photodynamic therapy was evaluated by the generation of reactive species which was demonstrated by chemical photodynamic efficiency assays. The low effect on cell viability and proliferation in the dark was demonstrated by in vitro assays using L929 fibroblasts. The FCarbPc fostered the inhibition of Staphylococcus aureus strain, therefore demonstrating the platform's potential in the treatment of dermatological infections of microbial nature.
