Amphiphilic Polymer Micellar Disruption Based on Main-Chain Photodegradation

Abstract

The amphiphilic block copolymer poly(ethylene oxide)-b-poly(N,N'-dihydroxypyromellitimide-hexamethylene diisocyanate) (PEO-b-PNH) with photocleavable N-O urethanes has been prepared to investigate the photodegradation of the hydrophobic main chain and therefore the disruption of copolymer micelles. Measurements of absorption and emission spectra, optical transmittance, DLS analysis, and TEM observations were applied. It was shown that PEO-b-PNH could self-assemble into flower compound micelles in water. The photodegradation of the hydrophobic polyurethane within the micellar core upon irradiation with 365 nm light could be conveniently controlled by changing the irradiation intensity; furthermore, complete micellar disruption could be achieved when 42% of N-O urethanes were photocleaved. By using DOX as the hydrophobic guest, the drug release profile showed a linear leakage of DOX out of the swelling polymer micelles in the initial stage and thereafter a much more quick exponential decay of DOX precipitation because of the micellar disruption upon further irradiation. The diffusion experiment of the leaked DOX into buffer solution (pH 7.4) showed that the DOX leakage could be prominently accelerated by a very short time of 365 nm irradiation, indicating that the N-O photocleavage can serve as a "turn-on" switch for the release of DOX in aqueous media.

An analytical approach for quantifying the influence of nanoparticle polydispersity on cellular delivered dose

“…In particular, considering solely the polydispersity arising from the nanoparticle synthesis can account for a 60% reduction in the NHDT. If the cellular association is proportional to the delivered dose [ 27 ], then the polydisperse population would show a significantly higher association with the cells. This highlights how critical it is to account for the polydispersity in a nanoparticle population.…”

“…However, these data are typically used only to measure the mean nanoparticle diameter and to ensure that the size distribution is unimodal. Nanoparticle transport through fluid is typically assumed to be governed by a combination of diffusion and sedimentation [ 27 , 33 , 34 ]. Both the diffusion and sedimentation parameters are nonlinear functions of diameter [ 24 , 34 ] and hence considering only the mean nanoparticle diameter may produce different estimates of the delivered dose, compared with considering the distribution of nanoparticle diameters.…”

Light and pH dual‐sensitive biodegradable polymeric nanoparticles for controlled release of cargos

“…Polymeric nanoparticles have undoubtedly received continuously increasing attentions due to their prospective applications, such as catalysis, biosensors and drug controlled release . Amphiphilic block copolymers (BCs) have been widely applied in drug delivery systems since it can self‐assemble into micelles in selective solvents and hydrophobic drug molecules are easily encapsulated into the hydrophobic core .…”

Progress in Research of Photo-controlled Drug Delivery Systems

“…利用光致断裂基团作为门控, 通过光照刺激实现门 控释药也是光致断裂型药物递送系统的一种新的设计 思路 [20,21] . Cui 等 [20] 利用光致断裂基团 ONB 作为维持 α-环糊精(α-CD)超分子纳米阀的塞子, 阻塞载药纳米颗粒 的介孔来控制药物分子的释放(图 14), 当该纳米复合物 用 980 nm 激光照射时, 通过上转换材料(吸收 λ: 980 nm, 图 12 肿瘤低氧微环境激活的光触发药物分子的释放 [50] Figure 12 Light-triggered drug released by the tumor hypoxic microenvironment activation [50] (NP: nanoparticle, PET: photo-induced electron transfer) 图 13 (a) YSUCNPs 在 NIR 光触发下释放药物机理示意图; (b)前药分 子 UV 光诱导断裂结构示意图; (c)荷瘤小鼠光触发治疗结果 [51] Figure 13 (a) The exploited mechanisms for NIR-regulated release of drugs from YSUCNPs; (b) the photocleavage reaction of prodrugs under UV light; (c) photographs of tumor-bearing mice injected with YSUCNP-ACCh, YSLnNP-ACCh and saline on the 1st day, and after treatment on the 9th day and 17th day [51] (YSUCNP-ACCh: ACCh-loaded yolk-shell structured upconversion nanoparticles; YSLnNP-ACCh: ACCh-loaded yolk-shell structured non-upconversion nanoparticles; Scale bars represent 1 cm) [52,53] , 1-乙酰基芘(1-Acetylpyrene) [54,55] , 苝 (Perylene) [56,57] , 钌配合物(Ruthenium complex) [58] 等. 图 14 NIR 光触发药物释放上转换纳米载药颗粒与光控释药过程 [20] Figure 14 Near-infrared light-triggered drug release of up-conversion nanoparticles and the process of light-controlled drug release (a: up-conversion nanoparticles(NaYF 4 :Tm.Yb), b: NaYF 4 , c: mesoporous silica(mSiO 2 ), d: α-cyclodextrin (α-CD)) [20] 3.2 光致异构型药物递送系统 光致异构型药物递送系统是一类含有光致异构化 基团的光响应性药物递送系统.…”