Overview
Poly-L-leucine (PLL) is a synthetic homopolymer derived from the amino acid L-leucine, characterized by its hydrophobic side chains and ability to form stable α-helical conformations. As a biodegradable polypeptide, it has gained prominence in biomedical and materials science due to its compatibility with biological systems and tunable physicochemical properties. The polymerization process allows control over chain length (typically 10-100 residues), which directly influences solubility and mechanical strength. Industrial production involves N-carboxyanhydride (NCA) ring-opening polymerization, yielding products with narrow molecular weight distributions when properly controlled.
Physical and Chemical Properties
PLL exhibits notable thermal stability up to 200°C, beyond which decomposition occurs rather than melting—a characteristic of many polypeptides. Its solubility profile is pH-dependent, with improved dissolution in acidic conditions where amino groups become protonated. The polymer's secondary structure transitions from random coil to α-helix as chain length increases, typically requiring ≥8 residues for stable helix formation. Hydrophobicity increases with polymerization degree, making higher molecular weight variants suitable for creating water-resistant films. Surface tension measurements show intermediate values (40-50 mN/m), allowing compatibility with both polar and non-polar matrices in composite materials.
Main Applications
In drug delivery systems, PLL serves as a hydrophobic core component in micelles for encapsulating poorly water-soluble therapeutics. Its biodegradability ensures controlled release without toxic byproducts. The material's self-assembly properties enable creation of nanostructures for targeted cancer therapies, often conjugated with polyethylene glycol (PEG) for enhanced circulation time. Tissue engineering utilizes PLL scaffolds for their structural integrity and cell-adhesive properties, particularly in bone regeneration applications. Industrial coatings benefit from its moisture barrier characteristics, with food-grade formulations used in edible packaging. Recent research explores antimicrobial surfaces by incorporating PLL into thin films.
Safety and Storage
While generally regarded as non-toxic, PLL powders require handling with NIOSH-approved N95 respirators to prevent respiratory irritation. Eye protection and gloves are recommended due to potential mild irritant effects. Material Safety Data Sheets (MSDS) should be consulted for specific handling protocols based on molecular weight and formulation. Long-term storage necessitates oxygen-free environments to prevent degradation. Vacuum-sealed packaging with desiccants is ideal, maintaining temperatures between 2-8°C. Solutions should be prepared in sterile buffers and used promptly or frozen at -20°C to prevent microbial growth or hydrolysis.
B2B Procurement Guide
Technical specifications should explicitly state: 1) Degree of polymerization (DP), 2) Molecular weight distribution (PDI), 3) Endotoxin levels (<0.1 EU/mg for biomedical use), and 4) Residual solvent content. Reputable suppliers provide NMR and HPLC characterization data. Bulk quantities (1kg+) typically offer 15-30% cost reductions. Consider custom synthesis for specialized DP requirements—lead times average 4-6 weeks. Quality certifications (ISO 13485 for medical-grade, GMP for pharmaceutical use) are critical for regulated applications. Sample testing should verify batch-to-batch consistency in dissolution behavior and impurity profiles.
Related Manufacturers
- 主营：牛筋面、甘氨酸、白色素、水苏糖、红曲黄、可可壳、海藻糖、儿茶素、干面条、食品果、精氨酸、胡萝卜、酪蛋白、磷酸氢、牛磺酸、食品bha、纤维素、茶氨酸、乳糖酶、醋酸钠、乳酸钠、黄原胶、沙棘黄、儿茶黑、黑豆红
- 主营：钛酸酯、阻燃剂、催化剂、彩色显影剂 CD-3、彩色显影剂 CD-4、L-丙交酯、邻苯三酚、左旋樟脑磺酸、右旋樟脑磺酸、三碘化硼、纳斯特试剂、抗氧剂1135、光稳定剂292、硅烷偶联剂
- 主营：饲料添加剂、食品添加剂、表面活性剂、亮氨酸、中间体、氧化物
- 主营：营养强化剂、增稠剂、甜味剂、亮氨酸、防腐剂、酸味剂、香精、抗氧化剂、改良剂、色素、提取物
- 主营：亮氨酸、亚铁氰化钾
- 主营：氧化剂、稀释剂、氧化钙、2-甲基萘、氟化钡、甲酸钠、对氯苯酚、氢氧化铋、对溴甲苯、高碘酸钠、氟硅酸铵、氢氧化钡、硫氰酸钾、对氯甲苯、二氯甲烷、氟化氢铵、橡胶防老剂、药物中间体、三正丙基胺、多乙烯多胺、电镀添加剂、尼泊金乙酯、邻氨基苯酚、食品保存剂、对甲苯磺酰氯
- 主营：杀菌剂、抛光剂、消毒剂、亮氨酸价格、鞣印染、催化剂、肥料中、擦光剂、磷酸三、pvc塑料、防水剂、润滑油、发酵粉、柔软剂、润滑剂、陶瓷器、饮用水、氧化钙、增香剂、抗臭剂、定香剂、香精中、缓蚀剂、诱变剂、纯甲醇、作皮革
- 主营：甘氨酸、甘氨酰、苯硫醚、聚合物、阻燃剂、月桂胺、酸性橙、去铁酮、豆油酸、二苯胺、西瓜酮、八乙基、硫酸锆、磺化钯、二氰基、硫酸锶、硫酸锰、二苯胍、铝酸锶、肌氨酸、四氢萘、磷酸铵、甲乙基、甲基亚、碳酸镁
- 主营：二乙基、仲辛酮、阻燃剂、聚合物、聚甘油、溴磷松、玉米素、基嘧啶、特乐酯、多果定、阿螨特、甲硫基、氮化镨、草除灵、橙叶油、灭虫隆、三甲胺、敌螨普、育畜磷、禾草灵、溶剂绿、惕格酸、碳酸镍、肉桂醛、分散蓝