scholarly journals Design of a Controlled-Release Delivery Composite of Antibacterial Agent Gatifloxacin by Spherical Silica Nanocarrier

2022 ◽  
Vol 9 ◽  
Author(s):  
Xueping Guo ◽  
Wenjing Mo ◽  
Dingyang Zhang ◽  
Yurong Wang ◽  
Fang Cao ◽  
...  

In this study, a spherical silica nanoparticle was explored as a gatifloxacin carrier synthesized by the chemical precipitation method. It was found that there was no new chemical bond formation during the loading process between gatifloxacin and silica, which implies that the binding was driven by physical interaction. In addition, the drug loading and encapsulation efficiency could be improved by appropriately increasing nano-silica content in the loading process. Meanwhile, the release rate of gatifloxacin after loading nano-silica was also improved, suggesting the successful design of a controlled-release delivery composite. The silica nanocarrier could significantly improve the antibacterial performance of Escherichia coli by 2.1 times, which was higher than the pure gatifloxacin. The 24 h bacteriostatic rate was higher than that of a simple mixture of silica nanoparticles and gatifloxacin. Strong reactive oxygen species (ROS) in GAT-SiO2 NPs suggests that ROS might be associated with bactericidal activity. The synergy between the physicochemical effect and ROS production of this material is proposed as the mechanism of its antibacterial activity, which can also be confirmed by the cell membrane damage observed under electron microscopy and DNA damage experiments. Collectively, our finding indicates that nano-silica microspheres could serve as a promising carrier for the sustained release of gatifloxacin, thereby providing a new carrier design scheme for the improvement of the antibacterial effect.

2020 ◽  
Vol 21 (7) ◽  
pp. 2586
Author(s):  
Chia-Hui Lin ◽  
Ranjith Kumar Kankala ◽  
Prabhakar Busa ◽  
Chia-Hung Lee

Since their invention, periodic mesoporous organosilicas (PMOs), an innovative class of materials based on organic as well as inorganic hybrid nanocomposites, have gathered enormous interest owing to their advantageous physicochemical attributes over the pristine mesoporous silica nanoparticles (MSNs). To further increase the interactions with the therapeutic guest species and subsequent compatibility as well as the physicochemical properties of PMOs, we demonstrate the post-hydroxylation of benzene-bridged PMO-based nanoparticles for photodynamic therapy (PDT). Initially, the hydrophobic benzene group in the PMO framework is modified through electrophilic substitution-assisted hydroxylation mediated by Fenton as well as Fenton-like reactions utilizing divalent and trivalent metal salts, respectively. These post-grafted PMOs with tuned hydrophobicity resulted in improved biocompatibility as well as drug loading efficiency through governing the interactions in host–guest chemistry by changing the physicochemical properties of the PMO frameworks. Furthermore, the photosensitizer, protoporphyrin IX (PpIX) molecules, encapsulated in the PMO frameworks showed a significant PDT effect in colon carcinoma (HT-29 cell line) and Gram-negative bacterial strain, Escherichia coli (E. coli). Furthermore, the light-induced cytotoxic properties in vitro are confirmed by various tests, including lactate dehydrogenase (LDH) assay for cell membrane damage and caspase assay for apoptosis determination. Indeed, the delivered PpIX molecules from PMOs generated deadly singlet oxygen species intracellularly under visible light irradiation, resulting in cell death through concomitantly triggered apoptotic caspases. Together, our findings demonstrate that this post-modified PMO design is highly advantageous and can be used as an effective PDT platform.


Author(s):  
Mustafa R. Abdulbaqi ◽  
Furqan M. Abdulelah

Objective: The scope of this study is to evaluate the influence of metal nanoparticles application on pharmaceutical properties and biologic activity of antifungal drug, metronidazole (MTZ). Method: Metal nanoparticles used in the study, bismuth sulfide (Bi2S3) used as the nanocarriers for metronidazole (MTZ) and they were synthesized by chemical co-precipitation method. Drug loading on Bi2S3 nanoparticles, lattice property alteration and average particles sizes were evaluated using fourier transform infra-red (FTIR) spectroscopy, atomic force microscopy(AFM), and powder x-ray diffraction(PXRD). The evaluation of the release of MTZ from Bi2S3 nanoparticles was carried out using USP type II rotating puddle apparatus. The antimicrobial activity of MTZ before and after loading was carried out by disc diffusion method against two aerobic gram +ve and one aerobic gram –ve bacteria, in addition to two fungi. Result: This study showed successful loading process as well as particles size reduction of MTZ after loading on Bi2S3 nanoparticles. In vitro release study showed significant* increase in solubility and dissolution of MTZ after loading on Bi2S3 nanoparticles. MTZ showed significant* increase in antibacterial (against gram +ve aerobic staphylococcus aureus and bacillus subtilis) and antifungal (Candida glabrata and Candida tropicalis) activities after loading process. Conclusion: Nanotechnology was applied successfully to improve both, solubility and biologic activity of the model drug used, metronidazole (MTZ).


2021 ◽  
Vol 147 ◽  
pp. 110286
Author(s):  
Christian E. Ziegler ◽  
Moritz Graf ◽  
Sebastian Beck ◽  
Achim M. Goepferich

Biomolecules ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1254 ◽  
Author(s):  
Xi Chen ◽  
Dong Chen ◽  
Linyuan Huang ◽  
Xiaoling Chen ◽  
Mei Zhou ◽  
...  

The peptides from the ranacyclin family share similar active disulphide loop with plant-derived Bowman–Birk type inhibitors, some of which have the dual activities of trypsin inhibition and antimicrobial. Herein, a novel Bowman–Birk type trypsin inhibitor of the ranacyclin family was identified from the skin secretion of broad-folded frog (Sylvirana latouchii) by molecular cloning method and named as SL-BBI. After chemical synthesis, it was proved to be a potent inhibitor of trypsin with a Ki value of 230.5 nM and showed weak antimicrobial activity against tested microorganisms. Modified analogue K-SL maintains the original inhibitory activity with a Ki value of 77.27 nM while enhancing the antimicrobial activity. After the substitution of active P1 site to phenylalanine and P2′ site to isoleucine, F-SL regenerated its inhibitory activity on chymotrypsin with a Ki value of 309.3 nM and exhibited antiproliferative effects on PC-3, MCF-7 and a series of non-small cell lung cancer cell lines without cell membrane damage. The affinity of F-SL for the β subunits in the yeast 20S proteasome showed by molecular docking simulations enriched the understanding of the possible action mode of Bowman–Birk type inhibitors. Further mechanistic studies have shown that F-SL can activate caspase 3/7 in H157 cells and induce apoptosis, which means it has the potential to become an anticancer agent.


2021 ◽  
Author(s):  
Delaram Poormoghadam ◽  
Bita Rasoulian Shiadeh ◽  
Fereshte Azedi ◽  
Hani Tavakol ◽  
Seyed Mahdi Rezayat ◽  
...  

Abstract Spinal cord injury (SCI) is a debilitating condition for which no definitive treatment has yet been identified. Noteworthy, it influences other tissues through inflammatory reactions and metabolic disturbance. Therefore, fingolimod (FTY-720) as an FDA-approved inflammatory modulator would be promising. In the present study, nanocarriers at two distinct monodisperse particle sizes of 60 (nF60) and 190 (nF190) nm were prepared.The neural stem cell (NSC) viability and LDH release were studied in the face of the nanocarriers and free FTY-720. Results indicated that nanocarriers and free FTY-720 enhanced NSC viability than the control group.However, nF190 significantly induced less cell membrane damage than nF60. Nanocarriers and free FTY-720 enhanced motor neuron recovery in SCI rats, while body weight and return to bladder reflux by nF190 was significantly higher than nF60 groups. Return to bladder reflux might be due to the role of FTY-720 in regulation of detrusor muscle tone and preservation of the integrity of vessels by acting on endothelial cells. Moreover,nF190 gained higher soleus muscle weight than the free drugs;probably decreasing pro-inflammatory cytokines in soleus diminish muscular atrophy in SCI rats.To sum thing up, larger nanacarrirs with less cell membrane damage seems to be more efficient than smaller ones to manage SCI.


2019 ◽  
Vol 32 (1) ◽  
pp. 1-6
Author(s):  
Nikita Verma

As a disease skin cancer has obtained different characteristics over the decades. Solar radiation that contains ultraviolet ray is the prime cause of skin cancer. In this present research, the nano-precipitation method was applied for preparing Quercetin loaded Nanoparticle (Qu-Nps) with much enhanced loading properties and improves incorporation of corresponding drugs. At the same time, the Quadratic model that takes help of the Response Surface Method was applied to observe the effects of some specific parameters maintained in the development of nanoparticle. Here, the sonication time was 20 min and delivery system F6 (with Drug: Polymer ratio of 1:45) provided optimum drug entrapment ability which is 70%. The optimized formulation for average size was almost 102.39 ±7.64 nm with zeta potential diameter averaging -28.43mV. Quercetin is a dietary flavonoid possessing multidimensional properties that is used in various other diseases including viral infection, bacterial infection, diabetes mellitus, and cancer. All outcomes support the view that Quercetin loaded nanoparticles (Qu-Nps) has high entrapment and drug loading abilities.


2021 ◽  
Author(s):  
Romina Mitarotonda ◽  
Martín Saraceno ◽  
Marcos Todone ◽  
Exequiel Giorgi ◽  
Emilio L Malchiodi ◽  
...  

Aim: Nanoparticles (NPs) interaction with immune system is a growing topic of study. Materials & methods: Bare and amine grafted silica NPs effects on monocytes/macrophages cells were analyzed by flow cytometry, MTT test and LIVE/DEAD® viability/cytotoxicity assay. Results: Bare silica NPs inhibited proliferation and induced monocyte/macrophages activation (increasing CD40/CD80 expression besides pro-inflammatory cytokines and nitrite secretion). Furthermore, silica NPs increased cell membrane damage and reduced the number of living cells. In contrast, amine grafted silica NPs did not alter these parameters. Conclusion: Cell activation properties of bare silica NPs could be hindered after grafting with amine moieties. This strategy is useful to tune the immune system stimulation by NPs or to design NPs suitable to transport therapeutic molecules.


Author(s):  
Yash S. Raval ◽  
Abdelrhman Mohamed ◽  
Jayawant N. Mandrekar ◽  
Cody Fisher ◽  
Kerryl E. Greenwood-Quaintance ◽  
...  

Wound infections are caused by bacteria and/or fungi. The presence of fungal biofilms in wound beds presents a unique challenge, as fungal biofilms may be difficult to eradicate. The goal of this work was to assess the in vitro anti-biofilm activity of a H 2 O 2 -producing electrochemical bandage (e-bandage) against 15 yeast isolates representing commonly-encountered species. Time-dependent decreases in viable biofilm CFU counts of all isolates tested were observed, resulting in no visible colonies with 48 hours of exposure by plate culture. Fluorescence microscopic analysis showed extensive cell membrane damage of biofilm cells after e-bandage treatment. Reductions in intracellular ATP levels of yeast biofilm cells were recorded post e-bandage treatment. Our results suggest that exposure to H 2 O 2 -producing e-bandages reduce in vitro viable cell counts of yeast biofilms, making this a potential new topical treatment approach for fungal wound infections.


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