Antibacterial Efficacy of Cellulose Acetate Nanocapsules Containing Nigella sativa Oil: A literature review

The rapid emergence of antimicrobial resistance (AMR) has intensified the search for novel plant-derived antibacterial agents with improved therapeutic efficacy and targeted drug delivery. Nigella sativa Linn. (Ranunculaceae), commonly known as Kalonji (black seed) or black cumin, has long been used in traditional medicine for the treatment of infectious and inflammatory disorders. Thymoquinone, the principal bioactive constituent of Nigella sativa essential oil, exhibits potent antibacterial, antioxidant, and anti-inflammatory activities. However, the therapeutic application of the essential oil is limited by poor stability, volatility, rapid degradation, and low bioavailability. Cellulose acetate (CA), a biodegradable, biocompatible, and non-toxic polymer, has emerged as a promising nanoencapsulation material that enhances drug stability, controlled release, and targeted delivery. This review evaluates the antibacterial potential of cellulose acetate nanocapsules loaded with Nigella sativa essential oil while summarizing the plant's phytochemical composition, antibacterial mechanisms, pharmaceutical applications, and Ayurvedic properties based on classical texts and contemporary scientific evidence. The reviewed literature demonstrates that Nigella sativa exhibits broad-spectrum antibacterial activity, particularly against Gram-positive bacteria, primarily through membrane disruption, oxidative stress induction, inhibition of biofilm formation, and suppression of bacterial metabolism by thymoquinone and related phytochemicals. Ayurvedic literature also describes Kalonji as Krimighna (antimicrobial) and Daurgandhyanashana (eliminates bad breath), supporting its traditional role in oral healthcare. Nanoencapsulation using cellulose acetate significantly improves the stability, bioavailability, sustained release, and antibacterial efficacy of Nigella sativa essential oil compared with conventional formulations. Overall, cellulose acetate nanocapsules represent a promising platform for developing advanced antibacterial therapeutics and oral healthcare products. Further in vivo studies, toxicological evaluations, pharmacokinetic investigations, and well-designed clinical trials are required to confirm their safety, efficacy, and clinical applicability.