Drug Modification Conjugation
Drug Bioonjugation Services

Targeted Drug Delivery Through Bioconjugation

The use of antibody-drug conjugates (ADCs) as guided missiles to target a specific group of cells with fewer side affects than traditional cancer treatment. The goal is to create a new molecule by conjugate drug with anti-cancer toxin attributes to antibodies and create a new molecule that essentially is greater than the sum of its parts by making it more targeted with stronger cytotoxic affect. Bio-Synthesis's bioconjugation-based drug discovery and development programs has built on over 30 years of experience in providing high quality conjugate complexes, commitment to R&D, and stringetn IP protection, our contract drug development program offer a comprehensive bioconjugation strategies that can be custom designed and developed to fit your needs. From design and development of conjugation strategy; feasibility studies; process development to purification and bioanalytical assessments, we have developed and delivered numerous drug bioconjugates such as:

  • Antibody-drug conjugates (ADCs)
  • Peptide-drug conjguates
  • Conjugation of drug to carrier proteins
  • Conjugation of toxin to antibody
  • Conjugation of macrocyclic metal chelator to drug
  • Natural compound-drug bioconjugate
  • Antisense oligo bioconjugate
  • Protein-drug bioconjugate
  • Recombinant protein modification
  • Drug-peptide-polymer bioconjugate
  • Drug-polymer bioconjugate
  • Oligomimetic-drug conjugate

Antibody-drug Conjugates (ADCs)

While traditional antibody conjugation takes advantage of lysine ϵ-amino , N-terminal α-amine groups or carboxylate groups due to its abundance in antibody, the conjugation procedure that tilize these groups often changes tthe overall pI of the antibody and leads to higher nonspecific binding. In addition, this random cross-linking within antibody often obscuring the binding sites and may produce partially active or inactive antiobdy conjugates tha tmay not bind to the antigen.

Bio-Synthesis offers site-specific antibody -drug conjugation services based on the unique conjugation strategy developed at Bio-Synthesis. Small drugs or toxins can be conjugated to an antibody at a specific site away from the antigen binding site. Site-specific cross-linking resutls in:

  • High retention antigen binding activity within the ensuing conjguate
  • Single or few predicatble sites labeling allow better manufacturing reporducibility
  • Specific binding (efficient and safe drugs).

Peptide-drug conjugates (PDC)

Peptide-drug conjugates (PDCs) developed at Bio-Synthesis using unique conjugation strategy. These drug molecule can be modified or conjugated at specific site on the peptide at customer's request.

Antisense and Oligonucleotide Drug Conjugates

Oligo-drug conjugates can be synthesized, modified, conjugate and characterized in our laboratories using site specific conjugation chemistries. Various oligonucleotide analogs can be preapre in our laboratory and conjugate with bioactive molecules, lipids, polymers to improve cellular uptake, pharmacokinetic properties and specificity towrd the tartet tissues/cells.

At Bio-Synthesis, custom bioconjugation complexes are manufactured under a strict quality control process to assure customers' complete satisfaction. Our sizeable investment in state-of-the-art analytical equipment provides industry-leading tools to develop and monitor our process. Complementary techniques, such as analytical chromatography and electrophoresis, MALDI-TOF, ESI, LC-MS are routinely used to verify that specifications are met. At Bio-Synthesis, we strive with competence and confidence to meet your demand for developing pre-clinical drug candidates or innovative regents and tools efficiently and affordably. With our track record, Bio-Synthesis is your ideal and reliable innovation partner in targeted drug discovery.

Contact our Technical Service Center at 800.220.0627 or contact us online with your detail project specifications, a project manager will be assigned to help you with design and develop an appropreate synthetic method for your specific needs.

Bio-Synthesis can assist our customer to conjugate peptide, oligonucleotides, antibody, carbohydrate with antibiotic, vitamine, anticancer drugs and other synthetic and natural drug compounds.

Vitamine Conjugation

Vitamine A, B1, B12, C and D conjugation, biotin can be cross-linked antibody, peptide/protein, oligonucleotides and other type of macromolecules.

Antibiotic Conjugation

We can provide conjugate antibody, peptide/protein or oligo/nucleic acid with antibiotic such as: Amoxicillin, clenbuterol, ractopamine, chloramphenicol, Salbutamol, Sulfamethazine, Sulfonamide group, Sulfadiazine, Sulfafurazole, Sulformetoxine, Sulfamethoxypyridazine,Sulfaguanidine, Sulfathiodiazole,Sulfamethoxazole, Sulfamethoxypyridazine, Sulfaguanidine, Sulfathiodiazole, Sulphamethoxydiazine, Sulfamonomethoxine, Madribon, Sulfaquinoxaline, Du-6859a, Streptomycin, Gentamycin,Ampicillin, Tetracycline

Small molecule and cancer drugs

List of available cancer drug can be used to conjugate with antibody, peptide/protein, oligonucleotide for targeted therapeutic are:

Doxorubicin, Epirubicin, Daunorubicin, Idarubicin, Elsamicin A, Actinomycin D, Bleomycin, Mithramycin, Taxol (Paclitaxel), Docetaxel, Tesetaxel, Vincristine, Vinblastine, Navelbine, Etoposie (VP-16), Beacizumab (Avastin), Cisplatin, Carboplatin, Erlotinib, Mitoxantrone, Busulfan, Nitrogen mustards, Uramustine, Chloroambucil, Melphalan, Cyclophophamid, Ifosfamide, Carmustine, Lomustine, Semustine, Procarbazine, Mitomycin, Praziquantel, Irinotecan, Topotecan, Methotrexate, Pemetrexed, lapatinib, Ambroxol, Demecolcine, CCP (3-cyano-2-chloropyridine), Tegafur-uracil, Mercaptopurine Thioguanine, Ara-C (cytarabine), Gemcitabine, Lamivudine, Capecitabine, Nelarabine, Fludarabine, Leustatin, Dacarbazine, Hydroxyurea, Rituximab, Tumor necrosis factor.

Other ADC Drug Conjugates

Aspirin, Ibuprofen, Ketoprofen, 5-Azacytidine, methotrexate, Lisinopril, Pravastatin, Memantine Hydrocloride, Propranolol

Standard Biomolecule Conjugation Service: BIOCON30000


Price varies based on the proejct specifications. Price does not includes cost of small molecule or biopolymer which requireed to be supplied by customer or order through Bio-Synthesis from a commercial vendor. Some of the small molecules are commerically available in an activated form. For non-active molecules, Bio-Synthesis can assit with the design and, if deemed necessary, biopolymer modification to introduce additional functional groups and extra linkers.
Please contact us for a quote.


Using preactivated small molecule and biomolecule with chemical reactive groups such as amine, thiol, carboxylate, hydroxyl, aldehyde and ketone, active hydrogen, photo-chemial and cycloadition reactions and cross link via zero-length , homobifunctional, heterobiofunctional or multifunctioanl cross-linking chemistries, denrimer and dendrons, cleavable regent system.

Service Specification:

After standard desalting, or purification, a small percent of heterogeneous products containing single or multi-site conjugate per molecule may exist.


All custom synthesis of biomolecule, modification or bioconjugation services are manufactured under strict quality control processes. Analytical HPLC and MS analyses are performed in every development cycle. Final target conjugates must first be isolated from excess or unreacted reagent. In many cases, simple dialysis may suffice to remove unreacted reagent from the reaction solution. Depending on the project scope, size-exclusion chromatography (SEC), HPLC, may also be used to either remove excess reagent or isolate and characterized the cross-linked product. Cross-linked target molecule may then be further characterized by biochemical or biophysical techniques. Once the product has been purified, it may be subject to many different types of studies including spectroscopic (MALDI-top, ESI, LC-MS Fluorescence), electrophoresis, immunochemical biochemical, enzymatical analysis. QC (quality control) and QA (quality assurance) procedures are also followed independently to offer you double guarantee for the highest quality possible of every delivered conjugates. Moreover, our dedicated technical account managers will guide your project through every step of the process and constantly keep you informed of the latest project progress.

Delivery Specifications:

The typical delivery consisted of lyophilized sample in individual fully labeled vials, shipment also contain COA, MS, HPLC and/or other analytical data . Additional analytical data also available upon requests.

Ordering and Submitting Requests for Bioconjugation Services

For us to better understand your customized project, please complete our Bioconjugation Service Questionnaire. The more our chemists understand your project’s needs, the more accurate your provided feedback will be. Providing us with your project’s details enables us to recommend the best reagents to use for your project. The most useful and readily available tools for bioconjugation projects are cross-linking reagents. A large number of cross-linkers, also known as bifunctional reagents, have been developed. There are several ways to classify the cross-linkers, such as the type of reactive group, hydrophobicity or hydrophilicity and the length of the spacer between reactive groups. Other factors to consider are whether the two reactive groups are the same or different (i.e. heterobifunctional or homobifunctional reagents), spacer is cleavable and if reagents are membrane permeable or impermeable. The most accessible and abundant reactive groups in proteins are the ϵ-amino groups of lysine. Therefore, a large number of the most common cross-linkers are amino selective reagents, such as imidoesters, sulfo-N-hydroxysuccinimide esters and N-hydroxysuccinimide esters. Due to the high reactivity of the thiol group with N-ethylmaleimide, iodoacetate and a-halocarbonyl compounds, new cross-linkers have been developed containing maleimide and a-carbonyl moieties. Usually, N-alkylmaleimides are more stable than their N-aryl counterparts.

In addition to the reactive groups on the cross-linkers, a wide variety of connectors and spacer arms have also been developed. The nature and length of the spacer arm play an important role in the functionality. Longer spacer arms are generally more effective when coupling large proteins or those with sterically protected reactive side-chains. Other important considerations are the hydrophobicity, hydrophilicity and the conformational flexibility. Long aliphatic chains generally fold on themselves when in an aqueous environment, making the actual distance spanned by such linker arms less than expected. Instead, spacers containing more rigid structures (for example, aromatic groups or cycloalkanes) should be used. These structures, however, tend to be very hydrophobic which could significantly decrease the solubility of the modified molecules or even modify some of their properties. In such cases, it is recommended to choose a spacer that contains an alkyl ether (PEO) chain. Bio-Synthesis offers several cross-linkers with PEO chains, such as thiol-binding homobifunctional reagents, heterobifunctional bases and their derivatives.

Within 3-5 days upon receiving your project scope, we will provide you an appropriate quotation. An order can be placed with PO (Purchase Order) or major credit cards ( ). Your credit card will be billed under Bio-Synthesis, Inc.