Custom Bioconjugation Services
Bioconjugation is the process of coupling two biomolecules together using a covalent linkage. Common types of bioconjugate chemistry are amine coupling of lysine amino acid residues (typically through amine-reactive succinimidyl esters), sulfhydryl coupling of cysteine residues (via a sulfhydryl-reactive maleimide or haloacetamide), and photochemically initiating free radical reactions, which have a broader reactivity. The product of these reactions is referred to as a bioconjugate.
Common bioconjugation procedures include coupling small molecules, such as biotin or fluorophores, to a protein, or protein-protein conjugations, such as the coupling of an antibody to an enzyme. Other less common molecules used in bioconjugation include oligosaccharides, nucleic acids, carbon nanotubes and synthetic polymers, such as polyethylene glycol (a.k.a. PEG). The KareBay? team of chemists is adept at all aspects of the bioconjugation process.
Small Molecule Polymer Conjugates Learn More
Polymer carriers can significantly modify the physicochemical properties of small molecule oral drugs to improve their therapeutic profile. In addition, polymer carriers can significantly enhance bioavailability, which allows oral administration of parenterally-delivered small molecule drugs that would otherwise have insufficient bioavailability on their own. This polymer platform allows for increased oral bioavailability, improved potency, modified bio-distribution with enhanced pharmacodynamics and reduced transportation across specific in vivo membrane barriers, such as the blood-brain barrier.
(a) A polymer can be conjugated to a small molecule drug via a stable linkage.
(b) The polymer-drug conjugate can be orally administered and then passes through certain cell membranes, such as the gut epithelial layer, to act on a target receptor on the cell surface. The drug-polymer conjugate can also be designed to display reduced ability to transport across specific membrane barriers within the body, such as the blood-brain barrier.
(c) A drug-polymer conjugate may also cross cell membranes to reach an intracellular target. The polymeric carrier could potentially increase a drug’s binding affinity with intracellular or extracellular targets.
Pro-Drug Conjugates Learn More
A drug can be turned into a pro-drug format to optimize the pharmacokinetics and pharmacodynamics as well as substantially increase both its efficacy and minimize its side effect profile. With this approach, these drugs can achieve enhanced bioactivity and, for example, increase the sustained exposure of active drugs to tumor cells in the body.
(a) Multiple Drug molecules are attached to a large molecular weight polymer in a multi-arm architecture in a pro-drug format.
(b) The drug molecules can also be conjugated to polymeric carrier via programmable releasable linkers. The linkers can be tailored to achieve the target product pharmacokinetic profile with a controllable release rate.
(c) The pro-drug molecules can be turned into the active parent form by triggers, such as pH or enzymatic hydrolysis. The linkers can be of different types, and can release the drug either sequentially or simultaneously to achieve the desired target pharmacokinetics profile needed to maximize therapeutic efficacy.
Large Molecule Polymer Conjugates
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