In vitro antibacterial activity of poly (amidoamine)-G7 dendrimer

Area of Science:

• Nanotechnology
• Materials Science
• Biomedical Engineering

Background:

• Growing antibiotic resistance necessitates novel antibacterial drug development.
• Nano-scale dendrimers are versatile synthetic macromolecules with applications in medicine and health.
• Traditional antibiotics contribute to the rise of bacterial resistance.

Purpose of the Study:

• To synthesize and characterize seventh-generation poly(amidoamine) (PAMAM-G7) dendrimers.
• To evaluate the antibacterial activity of PAMAM-G7 against Gram-negative and Gram-positive bacteria.
• To assess the cytotoxicity of PAMAM-G7 on human colon cancer cells (HCT116) and mouse embryonic fibroblast cells (NIH 3T3).

Main Methods:

• PAMAM-G7 synthesis using a divergent growth method.
• Structural and surface characterization via transmission electron microscopy, scanning electron microscopy, and Fourier transform infrared spectroscopy.
• Antibacterial activity assessed using Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) assays against various bacterial strains.
• Cytotoxicity evaluated using MTT assay on HCT116 and NIH 3T3 cell lines.

Main Results:

• PAMAM-G7 particles averaged approximately 20 nm in size.
• Effective inhibition of both Gram-positive and Gram-negative bacterial growth was observed.
• MIC50/MIC90 values ranged from 2-8 μg/ml, and MBC50/MBC90 values ranged from 64-256 μg/ml.
• Cytotoxicity was concentration and time-dependent, with significant reduction in cell viability at 0.85 μM after 72 hours.

Conclusions:

• PAMAM-G7 dendrimers demonstrate significant potential as novel antibacterial agents.
• The study highlights the efficacy of PAMAM-G7 against a range of bacterial pathogens.
• Further research into PAMAM-G7 could lead to new therapeutic strategies against resistant bacteria.