SPDP PEG

Small-molecule SPDP PEG ²
SPDP Peptide ⁴

Catalog No.	Name	M.W.	Purity
In stock BPG-4440	SPDP-PEG-Succinimidyl Valerate, MW 5K	N/A	N/A
In stock BPG-4439	SPDP-PEG-CH2CO2H, MW 1K-10K	N/A	N/A
In stock BPG-4438	SPDP-PEG-amine, MW 1K-5K	N/A	N/A

Background

SPDP PEG is a PEGylated long-chain SPDP cross-linker. SPDP is available in a variety of PEGylated forms, allowing longer spacer arm lengths. Since it is insoluble in water, organic solvents in the reaction mixture should be kept to a minimum using high concentrations of reagents in dimethylformamide (DMF) or dimethyl sulfoxide (DMSO). SPDP PEG contains pyridinedithiol (PDS) groups that allow selective conjugation of thiol-containing molecules such as proteins, peptides, and small molecules. Currently, SPDP PEG has been widely used in bioconjugation and drug delivery applications.

SPDP PEG

BOC Sciences is a leading supplier of specialty chemicals, including SPDP PEG products, with a strong focus on quality, reliability and customer satisfaction. We offer a full range of SPDP PEG products in various molecular weights and functional group modifications to meet the diverse needs of our customers. Whether you require small batches for research purposes or large batches for commercial production, BOC Sciences can meet your requirements efficiently and cost-effectively. If the SPDP PEG product you need is not in stock, we can also quickly synthesize high-quality SPDP PEG products according to your needs. If you are interested, please contact us for details of our services.

What is SPDP Crosslinker?

SPDP (succinimidyl 3-(2-pyridyldithio)propionate) is a heterobifunctional cross-linker with amine and thiol reactivity. It is usually first coupled to molecules containing primary amines through amide bonds under buffer conditions of pH 7.5 (6.5-8.5). Specific secondary coupling with molecules containing free thiol groups via a thiol-disulfide exchange reaction under buffer conditions at pH 8.0 (7.5-8.5). Additionally, this reagent can be used as a protected thiolation reagent after initial coupling and linker reduction. Since SPDP is insoluble in water (first dissolved in DMF or DMSO), the PEG linked to the middle arm of SPDP has better water solubility than ordinary -CH₂-, and the linked NHS-ester can better avoid protein aggregation. The applications of SPDP crosslinker mainly include:

Reversible cross-linking of proteins
Adding sulfhydryl groups to proteins by attachment to lysine residues
Formation of antibody-enzymes and other bioconjugates via two-step protein cross-linking
Hapten linked to carrier protein for antibody production
Preparation of immunotoxin conjugates

Characteristics of SPDP PEG

SPDP PEG is a water-soluble compound that can be easily functionalized with a variety of molecules through the reactive groups present in its structure. The succinimide ester groups in SPDP PEG react with primary amines to form stable amide bonds, while the pyridinedithiol groups react with thiols to form disulfide bonds.

Furthermore, the presence of the PEG spacer in SPDP PEG confers some important properties to the compound, including increased solubility, reduced immunogenicity, and increased circulating half-life. The flexibility and hydrophilicity of PEG also help protect the conjugated molecules from enzymatic degradation and immune recognition, making SPDP PEG an ideal platform for drug delivery and bioconjugation applications.

Applications of SPDP PEG

SPDP PEG for Bioconjugation

One of the major applications of SPDP PEG is the bioconjugation of biomolecules for various research and therapeutic purposes. By functionalizing proteins, peptides, and other molecules with SPDP PEG, researchers can improve their stability, solubility, and targeting capabilities. SPDP PEG has been used to create antibody-drug conjugates (ADCs), enzyme conjugates, and nanoparticle conjugates for targeted drug delivery and imaging applications.

SPDP PEG for Drug Delivery

SPDP PEG shows great promise as a drug delivery vehicle due to its ability to improve the pharmacokinetics and biodistribution of therapeutic agents. By conjugating drugs to SPDP PEG, researchers can control release kinetics, extend circulation half-life, and target specific tissues or cells. SPDP PEG-drug conjugates have been studied for the treatment of cancer, infectious diseases, and inflammatory diseases.

SPDP PEG for Biomaterials

SPDP PEG is also used to develop biomaterials for tissue engineering and regenerative medicine applications. By incorporating SPDP PEG into hydrogels, scaffolds, and nanoparticles, researchers can create materials with tunable mechanical properties, biodegradability, and bioactivity. SPDP PEG-based biomaterials have been investigated for wound healing, drug delivery, and tissue regeneration.

SPDP PEG Crosslinkers

DSPE-PEG-SPDP

DSPE-PEG-SPDP is a cross-linker composed of three main components: DSPE (1,2-Distaroyl-sn-glycero-3-phosphoethanolamine), PEG and SPDP. This cross-linker is widely used in the modification of liposomes, nanoparticles, and other lipid systems for drug delivery applications. DSPE provides lipid anchoring, PEG imparts water solubility and steric hindrance, and SPDP allows the introduction of functional groups for conjugation. The main feature of DSPE-PEG-SPDP is its ability to introduce thiol-reactive groups into the liposome surface. These thiol-reactive groups can then be used to conjugate various biomolecules (e.g., antibodies, peptides, or drugs) to liposome carriers. This combination enhances the targeting specificity and therapeutic efficacy of the cargo.

SPDP-PEG-Acid

SPDP-PEG-Acid is a cross-linker containing SPDP, PEG and carboxylic acid functional groups. This cross-linker is commonly used to modify proteins, peptides, and other biomolecules for various biotechnological applications. The carboxylic acid groups in SPDP-PEG-Acid allow primary amines to be conjugated to proteins, forming stable amide bonds. Applications of SPDP-PEG-Acid include protein labeling, surface functionalization, and bioconjugation. By modifying proteins with SPDP-PEG-Acid, researchers can attach fluorescent dyes, biotin tags, or other probes for imaging and detection purposes. This cross-linker is also used to immobilize proteins on surfaces for biosensor development and protein microarray fabrication.

SPDP-PEGn-NHS ester

SPDP-PEGn-NHS ester is a cross-linker containing SPDP, PEG, and N-hydroxysuccinimide (NHS) ester functional groups. This cross-linker is widely used for the conjugation of primary amines to biomolecules such as proteins and peptides for bioconjugation and drug delivery applications. The NHS ester groups in SPDP-PEGn-NHS ester specifically react with primary amines to form stable amide bonds. A distinctive feature of SPDP-PEGn-NHS ester is its high reactivity toward primary amines under mild conditions. This reactivity allows efficient and selective conjugation of biomolecules without the need for harsh chemical treatments. The PEG component of the cross-linker enhances water solubility and biocompatibility, making it suitable for biological applications.

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