Barman Sourav, Chakraborty Asmita, Saha Sujata, Sikder Kunal, Maitra Roy Sayoni, Modi Barkha, Bahadur Sabarnee, Khan Ali Hossain, Manna Dipak, Bag Pousali, Sarkar Ankan Kumar, Bhattacharya Rishi, Basu Arnab, Maity Amit Ranjan
Amity Institute of Biotechnology, Amity University, Kolkata, West Bengal 700135, India.
Department of Biomedical Science and Technology, The School of Biological Sciences, Ramakrishna Mission Vivekananda Educational Research Institute, Belur Math, Howrah, West Bengal 711202, India.
ACS Omega. 2023 Mar 30;8(14):12865-12877. doi: 10.1021/acsomega.2c08209. eCollection 2023 Apr 11.
The application of antimicrobial peptides has emerged as an alternative therapeutic tool to encounter against multidrug resistance of different pathogenic organisms. α-Melanocyte stimulating hormone (α-MSH), an endogenous neuropeptide, is found to be efficient in eradicating infection of various kinds of , including methicillin-resistant (MRSA). However, the chemical stability and efficient delivery of these biopharmaceuticals (i.e., α-MSH) to bacterial cells with a significant antibacterial effect remains a key challenge. To address this issue, we have developed a chitosan-cholesterol polymer using a single-step, one-pot, and simple chemical conjugation technique, where α-MSH is loaded with a significantly high amount (37.7%), and the final product is obtained as chitosan-cholesterol α-MSH polymer-drug nanoconjugates. A staphylococcal growth inhibition experiment was performed using chitosan-cholesterol α-MSH and individual controls. α-MSH and chitosan-cholesterol both show bacterial growth inhibition by a magnitude of 50 and 79%, respectively. The killing efficiency of polymer-drug nanoconjugates was very drastic, and almost no bacterial colony was observed (∼100% inhibition) after overnight incubation. Phenotypic alternation was observed in the presence of α-MSH causing changes in the cell structure and shape, indicating stress on . As a further consequence, vigorous cell lysis with concomitant release of the cellular material in the nearby medium was observed after treatment of chitosan-cholesterol α-MSH nanoconjugates. This vigorous lysis of the cell structure is associated with extensive aggregation of the bacterial cells evident in scanning electron microscopy (SEM). The dose-response experiment was performed with various concentrations of chitosan-cholesterol α-MSH nanoconjugates to decipher the degree of the bactericidal effect. The concentration of α-MSH as low as 1 pM also shows significant inhibition of bacterial growth (∼40% growth inhibition) of . Despite playing an important role in inhibiting bacterial growth, our investigation on hemolytic assay shows that chitosan-cholesterol α-MSH is significantly nontoxic at a wide range of concentrations. In a nutshell, our analysis demonstrated novel antimicrobial activity of nanoparticle-conjugated α-MSH, which could be used as future therapeutics against multidrug-resistant and other types of bacterial cells.
抗菌肽的应用已成为应对不同致病生物体多重耐药性的一种替代治疗工具。α-黑素细胞刺激素（α-MSH）是一种内源性神经肽，被发现对根除包括耐甲氧西林金黄色葡萄球菌（MRSA）在内的各种感染有效。然而，这些生物药物（即α-MSH）的化学稳定性以及将其有效递送至具有显著抗菌效果的细菌细胞仍然是一个关键挑战。为了解决这个问题，我们使用单步、一锅法且简单的化学偶联技术开发了一种壳聚糖-胆固醇聚合物，其中α-MSH的负载量显著高（37.7%），最终产物为壳聚糖-胆固醇α-MSH聚合物-药物纳米偶联物。使用壳聚糖-胆固醇α-MSH和单独的对照进行了葡萄球菌生长抑制实验。α-MSH和壳聚糖-胆固醇分别显示出50%和79%的细菌生长抑制率。聚合物-药物纳米偶联物的杀菌效率非常显著，过夜培养后几乎未观察到细菌菌落（约100%抑制）。在α-MSH存在的情况下观察到表型改变，导致细胞结构和形状发生变化，表明对[细菌名称未明确给出]有压力。作为进一步的结果，在用壳聚糖-胆固醇α-MSH纳米偶联物处理后，观察到细胞剧烈裂解并伴随细胞物质在附近培养基中的释放。这种细胞结构的剧烈裂解与扫描电子显微镜（SEM）中明显的细菌细胞广泛聚集有关。用不同浓度的壳聚糖-胆固醇α-MSH纳米偶联物进行剂量反应实验以解读杀菌效果的程度。低至1 pM的α-MSH浓度也显示出对[细菌名称未明确给出]细菌生长的显著抑制（约40%生长抑制）。尽管在抑制细菌生长中起重要作用，但我们的溶血试验研究表明壳聚糖-胆固醇α-MSH在广泛的浓度范围内具有显著的无毒特性。简而言之，我们的分析证明了纳米颗粒偶联的α-MSH具有新型抗菌活性，可作为未来对抗多重耐药[细菌名称未明确给出]和其他类型细菌细胞的治疗方法。
