Microwave-assisted and chemically tailored chlorogenic acid-functionalized silver nanoparticles of Citrus sinensis in gel matrix aiding QbD design for the treatment of acne

Background

Numerous studies have shown that various products of Citrus sinensis, for example, crude extracts, essential oil, and purified components, possess anti-acne properties. However, the development of chlorogenic acid-functionalized silver nanoparticles of C. sinensis in gel matrix aiding QbD design has not been evaluated for acne treatment.

Aim

In this study, we have developed chlorogenic acid-functionalized silver nanoparticles of C. sinensis in a gel matrix employing a QbD approach for acne treatment.

Material and Method

Citrus sinensis extract-loaded silver nanoparticles were functionalized with chlorogenic acid, which acted as a bio-reducing agent and further improved anti-acne properties. The developed formulation was optimized via Box-Behnken Design. The formulation morphology was evaluated by transmission electron microscopy (TEM). The release profile of C. sinensis extract formulation was assessed by an in vitro release study and confocal laser scanning microscopy (CLSM). Moreover, the characterization study of the gel was performed that included an evaluation of the extrudability and spreadability of the developed gel. Furthermore, the anti-oxidant efficacy of AgN-CA formulation was validated using the DPPH test.

Results

The results showed a particle size of 71.78 nm, a polydispersity index of 0.297, a zeta potential of −36.12 mV, and an entrapment efficiency of 79.42% ± 6.79%. The results also indicated a uniform particle size. The release profile of C. sinensis extract revealed that 73.95% of the drug was released, whereas CLSM pictures of mice skin evidently demonstrated that the rhodamine B-treated AgN-CA gel penetrated much more extensively in comparison to the control. Furthermore, the anti-oxidant efficacy of AgN-CA formulation was validated using the DPPH test. Moreover, the characterization study of the developed gel, including its extrudability and spreadability, was found to be 16.02 ± 3.21 g and 30.73 ± 5.94 g cm/s, respectively. Also, texture analysis findings revealed that AgN-CA gel had firmness, consistency, cohesiveness, and viscosity index of 159.69 g, 634.95 g s, −116.33 g, and −501.80 g s, respectively, indicating that the AgN-CA gel was stable.

Conclusion

The current study showed that AgN-CA is an effective drug carrier system for the topical administration of C. sinensis extract for the treatment of acne.     

Green synthesis and characterization of Solanum xanthocarpum capped silver nanoparticles and its antimicrobial effect on multidrug-resistant bacterial (MDR) isolates

Plant extracts and their bioactive compounds are considered as the promising options for green synthesis of nanoparticles instead expensive and hazardous materials. Here, Solanum xanthocarpum fruit was used for synthesis of silver nanoparticles (AgNP). The synthesized AgNPs were characterized by using chromatographic and spectroscopic analytical methods. AgNPs were confirmed by UV-visible absorbance at 420–470 nm. TEM analysis showed AgNP with 22.45 nm average size. X-ray diffraction studies revealed the crystalline and face central cubic nature of AgNPs. FTIR analysis revealed functional group present over AgNPs. The aminodiphenyl acetic acid, clomipramine, and fonisopril from fruit extracts were found to be major capping agents on AgNPs as a result of analysis by HRLC-MS. All clinical isolates showed resistance for ampicilline, amoxyclav, niladixic acid, and sulphafurazole, suggesting multidrug resistance. The results showed that all isolates were sensitive to AgNPs synthesized fruit extracts. On the contrary, all isolates were resistant to whole S. xanthocarpum fruit extracts alone. The antimicrobial activity of AgNP was explored against multidrug-resistant (MDR) Gram-negative clinical isolates including Escherichia coli, Shigella spp., Aeronomonas spp. and Pseudomonas spp. MIC values ranged between 1.25 mg/ml and 2.5 mg/ml at 8 McFarland's standards. Minimum bactericidal concentration was found to be in between 2.5 mg/ml to 5 mg/ml. Nanoparticles synthesized from fruit extract of S. xanthocarpum containing aminodiphenyl acetic acid, clomipramine, and fonisopril metabolites exhibit promising antimicrobial activity against MDR Gram-negative clinical isolates.     

In vivo transmission electron microscopy of the alternating structure of the protrusions between adjacent macrophage-like cells on micropatterns

ObjectivesWe investigated the behavior of macrophages in the defined microtopography of materials.MethodsPatterned cyclo-olefin polymer films were implanted into the femurs of seven-week-old rats. After 1 and 4 weeks, the rats were fixed with glutaraldehyde and OsO₄, and their bones were observed with transmission electron microscopy (TEM).ResultsTEM and segmentation revealed an alternating structure in which multiple protrusions of adjacent macrophage-like cells overlapped. They were approximately 2 μm long and almost uniform in width, and were induced by the limited topography.ConclusionNew structures appeared between the macrophage-like cells as a result of microtopography.     

Bonding performance of experimental HEMA-free two-step universal adhesives to low C-factor flat dentin

ObjectivesExperimental two-step universal adhesives (2-UAs) providing a particle-filled hydrophobic adhesive resin with a significant film thickness to hydrophobically seal the adhesive interface were designed and synthesized. This study aimed to characterize their interfacial interaction with dentin, to determine whether the 2-UA formulations achieve durable bonding to low C-factor flat dentin and to measure their water sorption.MethodsBonding effectiveness of 2-UAs that combine a 10-MDP-based primer with hydrophobic adhesive resins differing only for filler (BZF-21, BZF-29, and BZF-29_hv) were comparatively investigated with the commercial adhesive Clearfil SE Bond 2 (C-SE2, Kuraray Noritake). Adhesive-dentin interfaces were characterized with TEM. Adhesive-resin disks were immersed in distilled water at 37 °C for 1 week, 6 months and 1 year to measure water sorption and solubility. ‘Immediate’ and ‘aged’ micro-tensile bond strength (μTBS) of the adhesives applied in etch-and-rinse (E&R) and self-etch (SE) bonding mode to low C-factor flat dentin were measured. Statistical analyses involved linear mixed-effects (LME) modelling and Kruskal-Wallis testing (p < 0.05).ResultsTEM revealed that E&R hybrid layers were more sensitive to aging than SE hybrid layers. Lower water sorption was recorded for all UAs compared with C-SE2. The immediate μTBS of BZF-21 and BZF-29 was not significantly different from that of C-SE2. The 1-year aged μTBS of all 2-UAs was significantly lower than that of C-SE2, except for BZF-29 applied in E&R mode. A significant reduction in μTBS upon 1-year aging was recorded for BZF-21 and BZF-29 applied in E&R mode. A significant difference in μTBS between E&R and SE bonding modes was recorded for all adhesives except BZF-21.SignificanceExperimental 2-UAs with a hydrophobic adhesive-resin design produced± 20-μm thick adhesive-resin layers, absorbed less water and resulted in bonding performance that was more aging-resistant when applied in SE than in E&R bonding mode. The silica-filled BZF-29 2-UA revealed the most comparable bonding performance with C-SE2 in a low C-factor condition (flat dentin).