Polymersome‐mediated intracellular delivery of antibiotics to treat Porphyromonas gingivalis ‐infected oral epithelial cells

Abstract

The gram-negative anaerobe Porphyromonas gingivalis colonizes the gingival crevice and is etiologically associated with periodontal disease that can lead to alveolar bone damage and resorption, promoting tooth loss. Although susceptible to antibiotics, P. gingivalis can evade antibiotic killing by residing within gingival keratinocytes. This provides a reservoir of organisms that may recolonize the gingival crevice once antibiotic therapy is complete. Polymersomes are nanosized amphiphilic block copolymer vesicles that can encapsulate drugs. Cells internalize polymersomes by endocytosis into early endosomes, where they are disassembled by the low pH, causing intracellular release of their drug load. In this study, polymersomes were used as vehicles to deliver antibiotics in an attempt to kill intracellular P. gingivalis within monolayers of keratinocytes and organotypic oral mucosal models. Polymersome-encapsulated metronidazole or doxycycline, free metronidazole, or doxycycline, or polymersomes alone as controls, were used, and the number of surviving intracellular P. gingivalis was quantified after host cell lysis. Polymersome-encapsulated metronidazole or doxycycline significantly (P<0.05) reduced the number of intracellular P. gingivalis in both monolayer and organotypic cultures compared to free antibiotic or polymersome alone controls. Polymersomes are effective delivery vehicles for antibiotics that do not normally gain entry to host cells. This approach could be used to treat recurrent periodontitis or other diseases caused by intracellular-dwelling organisms.

iRGD peptide conjugation potentiates intraperitoneal tumor delivery of paclitaxel with polymersomes

“…We have demonstrated that the POEGMA-PDPA polymersomes retain the drug inside for several weeks at neutral pH and quickly release the cargo at mildly acidic pH [27]. pH-sensitive polymersomes have been used for intracellular delivery of DNA [29], antibodies [33–35], antibiotics [36], cytotoxic drugs [27,37,38], and peptides [39]. Systemic cargo delivery with polymersomes in solid tumors in mice as well as tumor imaging has been potentiated by affinity targeting with ligands such as RGD peptide [40], PR_b-peptide [41], or transferrin [42,43].…”

Paclitaxel-Loaded Polymersomes for Enhanced Intraperitoneal Chemotherapy

“…PDPA-based polymersomes have been used for intracellular delivery of DNA (14), antibodies (15), antibiotics (28), anticancer drugs (12,13), and peptides (29). Particularly, for cancer cells, an efficient cytoplasmic delivery improves the drug efficacy (12).…”

The Periodontal Pathogen Porphyromonas gingivalis Preferentially Interacts with Oral Epithelial Cells in S Phase of the Cell Cycle

“…H357 cells were then incubated with the P. gingivalis suspension for 90 min at 37°C. Cells were washed with PBS to remove nonadherent bacteria and treated with 200 g ml Ϫ1 metronidazole (Sigma, United Kingdom) in DMEM for 1 h at 37°C to kill adherent external bacteria (2). Cells were then washed three times with PBS and lysed with distilled water for 30 min, with mechanical scraping and agitation to release the internalized bacteria (24).…”

“…P. gingivalis has the ability to invade a variety of host cells, including oral keratinocytes (2), through numerous surface-associated virulence factors such as fimbriae (3), hemagglutinins (4), and gingipain proteases (5). The invasion strategy provides a considerable value for bacterium survival, as it could protect periodontal pathogens from host defense mechanisms and assist in their persistence within a site of infection, leading to continuous periodontal inflammation.…”