Overview
PEG-modified reactive groups are polyethylene glycol (PEG) derivatives engineered with functional moieties (e.g., NHS esters, maleimide, thiols, or azides) for covalent conjugation to biomolecules. They are widely used in pharmaceuticals, biotechnology, and materials science to enhance solubility, prolong circulation time, and reduce immunogenicity. The PEG backbone provides a hydrophilic, non-toxic spacer, while the reactive group enables site-specific attachment to proteins, peptides, or surfaces. These compounds are classified by PEG molecular weight (e.g., PEG 2k, 5k) and reactivity (e.g., amine-reactive, thiol-reactive). Heterobifunctional PEGs (e.g., NHS-PEG-MAL) allow sequential conjugation of two different molecules, expanding their utility in complex bioconjugation workflows.
Physical and Chemical Properties
PEG-reactive groups exhibit high water solubility due to the PEG chain's ethylene oxide units, which form hydrogen bonds with water. The reactivity depends on the functional group: NHS esters hydrolyze in aqueous solutions (t1/2 ~1–4 hours at pH 7.4), while maleimide groups react selectively with thiols at pH 6.5–7.5. Azide-modified PEGs participate in click chemistry (e.g., CuAAC with alkynes). Thermal stability is moderate, with decomposition typically occurring above 150°C. PEGs are hygroscopic and require anhydrous storage to prevent hydrolysis of reactive groups. Analytical characterization includes NMR (to confirm PEG length) and UV/vis or HPLC (to quantify reactive group density).
Main Applications
In drug delivery, PEGylation (attachment of PEG to therapeutics like proteins or siRNA) reduces renal clearance and minimizes immune recognition. For example, PEG-NHS esters conjugate to lysine residues on antibodies for ADC (antibody-drug conjugate) development. Maleimide-PEGs link to cysteine-containing peptides for targeted therapies. In diagnostics, PEG-azides enable bioorthogonal labeling via click chemistry. Surface modification uses PEG-silanes or PEG-thiols to create non-fouling coatings on medical devices. PEG-based crosslinkers (e.g., PEG-diacrylate) are also used in hydrogels for tissue engineering due to their tunable mechanical properties and biocompatibility.
Safety and Storage
Most PEG-reactive groups are low-toxicity (LD50 >2 g/kg orally in rats) but require precautions for reactive moieties. NHS esters and maleimides may cause skin/eye irritation; use gloves and goggles. Azides should be treated as potential explosives if concentrated. Storage conditions vary: NHS-PEGs are moisture-sensitive and often shipped desiccated at –20°C. Thiol-PEGs oxidize readily and require argon packing. For long-term stability, lyophilized powders are preferred over solutions. Always check SDS for specific derivatives, as stability can range from days (e.g., hydrazide-PEG) to years (PEG-alkynes).
B2B Procurement Guide
When sourcing PEG-reactive groups, specify: (1) PEG molecular weight (e.g., 1kDa, 5kDa), (2) functional group type and purity (>95% recommended), (3) monofunctional/bifunctional design, and (4) end-group modification (e.g., methoxy termination). Bulk orders (≥100g) may reduce costs by 20–30%. Suppliers like Sigma-Aldrich, JenKem Technology, and Creative PEGWorks offer custom synthesis. Lead times for specialty PEGs (e.g., multi-arm PEG-NHS) can exceed 8 weeks. Request COA (Certificate of Analysis) with HPLC/NMR data. For GMP-grade PEGs (used in FDA-approved drugs), expect 3–5x higher pricing due to stringent testing requirements.
Related Manufacturers
- 主营：嵌段共聚物、合成磷脂、荧光染料、点击化学、PEG、量子点
- 主营：反应活、hydrazide、催化剂、修饰剂、活性脂、糖蛋白、连接子、激动剂、聚合物、胆固醇、钆特酸、催化性、dna标记、络合剂、荧光试剂、雨蛙素、乙二胺、ped结构、衍生物、化合物、链接剂、反应物、生物素
- 主营：在水中、包含肽、含叠氮、peg单元、peg试剂、aminopeg8、bcn基团、丙炔基、由氨基、菁染料、具有炔、胺hcl盐、阿尔法、催化剂、结构式、氨基nh2、3694-51-7、碘化物、4727-50-8、具有两、带有炔、磺酸基、3065-79-0、甲基九、荧光素
- 主营：活性酯、荧光染料、花青素染料
- 主营：磷脂聚乙二醇、胆固醇聚乙二醇、PLGA、功能化聚乙二醇、硬脂酸聚乙二醇、透明质酸、聚乙内酯、聚乳酸、葡聚糖、DOPE
- 主营：金纳米、三角片、麦芽糖、修饰tio2、羟丙基、ito薄膜、氮化钛、tio2纳米、碳粉tio2、pd纳米笼、水溶伊红、纳米复合、磁性纳米、蛋白芯片、包硅金银、硅纳米线、包硅纳米、硅纳米管、螯合树脂、油溶性银、复合材料、薄膜定制、纳米粒子
- 主营：胆固醇荧光探针、罗丹明B酰肼、深红溶酶体荧光探针、缺氧探针、鬼笔环肽、钙黄绿素红、钙螯合剂