Alex Brown

As an amphiphilic polymer, PEG can be soluble in water and most organic solvents, and has the characteristics of good biocompatibility, non-toxicity, and low immunogenicity. It can be excreted through the kidneys, so there will be no accumulation phenomenon in the body. For a long time, PEG is a commonly used as pharmaceutical excipient, which has been widely applied in various medicaments such as soft ointment, suppository, drop pill, hard capsule, eye drop, injection and tablet.   Role of PEGs   Solubilizers   Resistance to mould growth and rancidity makes PEG an ideal excipient for liquid dosage forms. PEGs minimizes the need of harsh solvents needed during encapsulation. For example, Liquid PEGs (PEG 200 to PEG 600) can be used as a water miscible solubilizer in oral liquids and parenterals. High MW PEGs have been widely used for microencapsulation of active drug. PEG can be used as a lubricant in eye drops.   Permeation Enhancer   PEGs itself ... Continue reading →

Cyclic amino acids are a class of amino acids that contain a cyclic structure in their side chain. These amino acids typically have a different structure compared to the standard amino acids found in proteins. One example of a cyclic amino acid is proline, which has a five-membered ring structure in its side chain. Proline is unique because its cyclic structure limits the flexibility of the polypeptide chain, disrupting protein folding. It is commonly found in turns and loops of proteins. Another example is hydroxyproline, which is a derivative of proline. It contains a hydroxyl group (-OH) attached to the side chain nitrogen, adding a polar character to the amino acid. Cyclic amino acids can have diverse biological functions. Some can act as neurotransmitters, while others serve as precursors for the synthesis of important biomolecules. Studying and understanding the properties of cyclic amino acids is crucial in various fields, including biochemistry, pharmacology, and medicinal ... Continue reading →

Liver cancer is considered the second leading cause of cancer-related deaths in the world. It has the characteristics of a high recurrence rate and low early detection rate, and it is a highly invasive and destructive disease. HepG2 is a human liver cancer cell line, most commonly used in drug metabolism and liver toxicity studies. HepG2 cells are non-tumor-causing cells with a high proliferation rate and epithelioid morphology, which can perform various differentiated liver functions. Originally, HepG2 was derived from the liver cancer tissue of a 15-year-old white man, and this cell secretes various plasma proteins, including serum proteins, alpha 2-macroglobulin, haemofibrinolytic plasminogen, iron transferrin, etc. A study has proved that HepG2 cells are resistant to G418. Moreover, HepG2 cells and their derivatives are used as a model system for studying liver metabolism and xenobiotic toxicity, antigen toxicity and genotoxic drugs, understanding the occurrence of liver cancer, ... Continue reading →

Compound 1,3-dimethyl-2'-deoxypseudoUridine is a C-nucleoside isomer of 1,3-dimethyl-2'-deoxyuridine. The 1,3-dimethyl-2'-deoxypseudoUridine can be synthesized from 1,3-dimethylpseudoUridine which can be obtained directly by treatment of pseudoUridine with dimethylformamide dimethyl acetal. PseudoUridine is commonly observed in ribosomal RNA (rRNA), and it is prevalent in transfer RNA (tRNA), small nuclear RNA (snRNA) and other noncoding RNAs (ncRNAs). In addition, the discovery of the presence of PseudoUridine in yeast and human messenger RNAs (mRNAs) encourages people to explore the probable effects of PseudoUridine in mRNA. Recently, the importance of PseudoUridine in epigenetic modulation of mRNA function is becoming increasingly apparent. The functions of pseudoUridine and its derivatives, whether naturally occurring or chemically synthesized, remain to be discovered in many of the cases. Naturally occurring pseudoUridine derivatives in RNA modification The ... Continue reading →

The biotin labeled peptide contains a special functional region and an unmodified peptide equivalent to a reference, which can be anchored on avidin conjugated magnetic beads and incubated with the target sample (such as nuclear extract or purified recombinant protein). The unbound protein was removed by washing, and then the bound protein was eluted. SDS/ PAGE analysis could be observed directly by protein staining. By comparing the proteins that bind to modified and unmodified peptides respectively, it is possible to identify candidates, that is, "reader" proteins of specific functional proteins. Biotin labeled peptides with some special modifications can be chemically synthesized with a purity of more than 80%. Application Biotin labeled peptides can be used for protein purification, detection, curing, drug targeting, protein structure analysis and so on. The simplest way to detect a substance that interacts with a polypeptide is to use the peptide to do ... Continue reading →

Nucleic acid-polymer conjugates are afforded by click reactions of appropriately functionalized oligonucleotides with synthetic polymer chains of different chemical nature, composition, and properties. With expertise in bioconjugation, BOC Sciences has developed various strategies to offer tailor-made nucleic acid-polymer conjugation, protein-polymer conjugation, peptide-polymer conjugation, viruses-polymer conjugation, enzymes-polymer conjugation, liposome-polymer conjugation and carbohydrate-polymer conjugation services to our institutional and industrial customers.   Introduction of Nucleic Acid-polymer Conjugates Nucleic acids can be bioactive in different forms (i.e., DNAzymes, aptamers, siRNA, etc.), thus imparting both structural and functional features for designing sophisticated biohybrid materials. The self-assembly of DNA strands is partly due to the intermolecular formation of H-bonds between the complementary purine (adenine and guanine) and pyrimidine (thymine and ... Continue reading →

The cytotoxic payload or warhead is an important part of ADC. It is activated after being released from ADC in the cytoplasm of tumor cells and can destroy tumor cells even at low doses.   The antibody component in ADC cannot carry a large amount of cytotoxic payload due to its structure. Therefore, the cytotoxic payload in the new generation of ADCs must be extremely toxic to eliminate most tumor cells, even with minimal payload delivered.   ADC cytotoxic agents need to be studied under in vitro conditions to determine whether they are a substrates, inhibitors, or inducers of metabolic enzymes (such as cytochrome P-450 isoenzymes (CYP), and certain transport enzymes, etc.). These studies help to clarify the elimination/enhancing effects of in vivo factors on cytotoxic agents.   The cytotoxic payload should also remain stable during blood preparation or storage and circulation. Incompletely stable cytotoxic payloads may be transformed into undesirable drugs during ... Continue reading →

B Cell Receptor (BCR) signaling pathway overview BCR is a transmembrane protein complex that controls B cell maturation, survival, apoptosis, and the production of plasma cell antibodies starting from the expression form of pro-BCR and pre-BCR. BCR signaling is connected by a network of kinases and phosphatases, and its pathways can be divided into two types: chronically activated BCR and tetanic BCR. Chronically activated BCR is an antigen-dependent process, mainly using NF-kB and MAPK/ERK pathways. Tetanic BCR is antigen-independent and maintains the survival of B cells through PI3K/AKT pathways. BTK, a non-receptor intracellular kinase, belongs to the TEC family of tyrosine kinases and is an important part of the BCR signaling pathway. BTK protein consists of 659 amino acids and 5 domains (PH, TH, SH3, SH2, kinase domain), among which Y223 of the SH3 domain and Y551 of the kinase domain are two key tyrosine phosphorylation sites. types of BTK inhibitors and their binding sites ... Continue reading →