Acid‐Labile Amphiphilic PEO‐b‐PPO‐b‐PEO Copolymers: Degradable Poloxamer Analogs

Abstract

Poly ((ethylene oxide)-b-(propylene oxide)-b-(ethylene oxide)) triblock copolymers commonly known as poloxamers or Pluronics constitute an important class of nonionic, biocompatible surfactants. Here, a method is reported to incorporate two acid-labile acetal moieties in the backbone of poloxamers to generate acid-cleavable nonionic surfactants. Poly(propylene oxide) is functionalized by means of an acetate-protected vinyl ether to introduce acetal units. Three cleavable PEO-PPO-PEO triblock copolymers (Mn,total = 6600, 8000, 9150 g·mol(-1) ; Mn,PEO = 2200, 3600, 4750 g·mol(-1) ) have been synthesized using anionic ring-opening polymerization. The amphiphilic copolymers exhibit narrow molecular weight distributions (Ð = 1.06-1.08). Surface tension measurements reveal surface-active behavior in aqueous solution comparable to established noncleavable poloxamers. Complete hydrolysis of the labile junctions after acidic treatment is verified by size exclusion chromatography. The block copolymers have been employed as surfactants in a miniemulsion polymerization to generate polystyrene (PS) nanoparticles with mean diameters of ≈200 nm and narrow size distribution, as determined by dynamic light scattering and scanning electron microscopy. Acid-triggered precipitation facilitates removal of surfactant fragments from the nanoparticles, which simplifies purification and enables nanoparticle precipitation "on demand."

Acid-Labile Surfactants Based on Poly(ethylene glycol), Carbon Dioxide and Propylene Oxide: Miniemulsion Polymerization and Degradation Studies

“…Removal of the surfactant from the formed nanoparticles might be desirable for several applications, since a large amount of surfactant can be problematic, because of cytotoxicity or interfere with film forming properties of the dispersion [6,7]. In this context a promising strategy is the degradation of the surfactant or switching its amphiphilicity by an external trigger, e.g., pH variation or redox conditions directly in the dispersion [8][9][10]. Aliphatic polycarbonates are degradable and therefore promising materials for degradable surfactants.…”

F127 poloxamer effect on cytotoxicity induction of tumour cell cultures treated with doxorubicin

“…This event,in turninduces apoptosis by both cytochrome C release and p38 MAPK activation. [27] Considering the acidic environment of HCC tissue, the copolymer studied herein might be further slightly modified [28] to generate acid-cleavable non-ionic surfactants targeting its delivery to the tumour, and hence, increasing the efficacy and selectivity of the antitumoral treatment, and lowering individual and cumulative anthracycline doses. Likewise, it is tempting to speculate that this general phenomenon might also occur with recently proposed HCC systemic therapeutics (such as regorafenib, approved by FDA in 2017).…”

Chemical Destabilization of Fresh and Spent Cutting Oil Emulsions: Differences between an Ecofriendly and Two Commercial Synthetic Lubricants

“…pH neutralization led to a further decrease of the NIS concentration, which reached the lowest value (25 mg/L) after treatment with 20-g/L sulfuric acid. Notably, the addition of the acid determined the degradation of the surfactant compounds with formation of products as carboxylic acid or alcohols, which contributed to the NIS reduction in the aqueous phase [33,34]. This result was more effective with the increase of the sulfuric acid dosage.…”