Liposomes with Water as a pH‐Responsive Functionality for Targeting of Acidic Tumor and Infection Sites

Abstract

Al ipid named DCPAw as synthesized under microwave-assisted heating. DCPAp ossesses ap yridine betaine,h ydrophilic group that can be complexed with water through hydrogen bonding (DCPA-H 2 O). DCPA-H 2 Ol iposomes became protonated relatively fast already at pH < 6.8, due to the high HOMO binding energy of DCPA-H 2 O. In murine models,D CPA-H 2 Ol iposomes had longer blood circulation times than natural DPPC or cationic DCPM liposomes,w hile after tail-vein injection DCPA-H 2 Ol iposomes targeted faster to solid tumors and intra-abdominal infectious biofilms.T herapeutic efficacy in am urine,i nfected wound-healing model of tail-vein injected ciprofloxacin-loaded DCPA-H 2 Ol iposomes exceeded the ones of clinically applied ciprofloxacin as well as of ciprofloxacin-loaded DPPC or DCPM liposomes.

pH-Responsive Nanocarriers in Cancer Therapy

“…Wang et al [ 74 ] synthesized a novel zwitterionic lipid 2-(4-((1,5-bis(octadecyloxy)-1,5-dioxopentan-2-yl) carbamoyl) pyridin-1-ium-1-yl) acetate (DCPA) and used water as the pH-responsive functional group. The DCPA-H 2 O liposomes were loaded with the red-fluorescent rhodamine dye as a model drug.…”

Guanidinium‐Decorated Nanostructure for Precision Sonodynamic‐Catalytic Therapy of MRSA‐Infected Osteomyelitis

“…Considering the infection microenvironment conditions (e.g., hypoxia, [12] acidic pH, [13] toxins, [3] and overexpressed H 2 O 2 from immune cells [14] ), activatable nanocomposites have been designed to sense and respond to such endogenous triggers, enabling selective activation of the payload at the desired destination for optimal therapeutic efficacy, along with the reduced adverse effect on normal cells and tissues. [15] However, relying on pre-existing pathological conditions, passively endogenoustriggered strategies are limited by large heterogeneity at the infection site and individual variation.…”

“…An additional peak at 1145 cm −1 possibly associated with carbonfluorine bond, confirmed the presence of trifluoroacetic acid ligand of guanidinium. The final nano composite was further characterized via solid-state 13 C cross-polarization/magic-angle-spinning (CP/MAS) NMR spectroscopy. As shown in Figure S11 in the Supporting Information, owing to the presence of PG on the surface of Au/TNT, an obvious signal occurred at δ 13C = 170-180 ppm, indicating the presence of a large amount of carbonyl groups.…”

Proton-mediated burst of dual-drug loaded liposomes for biofilm dispersal and bacterial killing

“…DCPA was prepared as previously described [20] and the chemical structure was identified by 1 H NMR. PEG 2K -ciprofloxacin was prepared according to the following procedure.…”

“…However, confining cargo release from liposomes to a target site requires conjugation of stimuli-responsive functionalities with membrane lipids that may disrupt the physico-chemical balance in the lipid membrane of liposomes [17,19]. Recently, we synthesized a lipid named DCPA (2-(4-((1,5-bis(octadecenoyl)1,5-dioxopentan-2-yl)carbamoyl) pyridin-1-ium-1-yl)acetate) that complexes with water through hydrogen bonding (DCPA-H 2 O) [20]. Water molecules in DCPA-H 2 O liposomes provide a stealth functionality that allows long-time blood circulation, while becoming protonated below pH 6.8 allowing fast selftargeting to infectious biofilms after tail-vein injection in mice.…”