L-Arginine (L-Arg) depletion has attracted great attention in cancer therapy. Although two types of arginine-depleting enzymes, arginine deiminase (ADI) and human arginase I, are undergoing clinical trials, random site of PEGylation, low efficacy of heavy metal as co-factor, and immunogenicity limit the performance of these drugs and cause difficulty in a homogeneous production. Here we screened ten catalytic metal ions and have successfully produced a site-specific mono-PEGylated human arginase I mutant by conjugating the Cys45 residue to PEG-maleimide to minimize the decrease in activity and produce a homogeneous product. The catalytic efficiency trend of metal ion–enriched human arginase I mutant (HAI) was Co2+ > Ni2+ ≫ Mn2+. The overall kcat/KM values of Co-HAI and Ni-HAI were higher than Mn-HAI by ~ 8.7- and ~ 5.2-folds, respectively. Moreover, the results of enzyme kinetics and circular dichroism spectrometry demonstrated that the 20 or 40 kDa linear and branched PEG attached on the HAI surface did not affect the enzyme activity and the protein secondary structures. In vitro studies showed that both Co-HAI-PEG20L and Ni-HAI-PEG20L inhibited the growth of eight types of cancer cell lines. The pharmacodynamic study in mice demonstrated that the i.p. administration of Co-HAI-PEG20L at 13 mg/kg and Ni-HAI-PEG20L at 15 mg/kg was able to maintain a L-Arg level below its detection limit for over 120 h after one injection. The body weights of mice could return to normal levels within 5 days after injection, showing that the doses were well-tolerated. Therefore, both the Ni-HAI-PEG20L and Co-HAI-PEG20L are promising candidates for cancer therapy. SINOPEG can supply linear PEG-maleimide: Chung S F ,  Kim C F ,  Tam S Y , et al. A bioengineered arginine-depleting enzyme as a long-lasting therapeutic agent against cancer[J]. Applied Microbiology and Biotechnology, 2020, 104(6). https://doi.org/10.1007/s00253-020-10484-4

Plant-derived cholesterol is the most important raw material component in mRNA vaccine production and gene therapy. As one of the key functional excipients of lipid nanoparticles (LNPs), cholesterol plays a role in mediating LNP endocytosis as well as stabilizing the LNP structure (cholesterol helps increase the fluidity or stiffness of cell membranes and the addition of cholesterol improves the stability of nanoparticles). Meanwhile, with the rapid development of related research, lipid-based drug delivery systems are becoming increasingly important in a wider range of therapeutic areas, including vaccines for infectious diseases, cancer immunotherapy, etc. SINOPEG supplies to the market plant-derived cholesterol products of non-animal origin without genetic risk, eliminating concerns about the risk of animal-derived cholesterol carrying animal viruses, and can be used in high-end formulation excipients: small molecule liposomal drugs, nucleic acid drugs, mRNA vaccines and non-animal-derived cell culture media for protein-based drugs.

Welcome to visit us at SINOPEG's Booth #2351 at BIO International Convention 2022, San Diego, USA from 13th to 16th June. SINOPEG is mainly engaged in drug delivery system (DDS) and new medical materials business. SINOPEG has a high-level team with strong technical reserve to research, develop and produce high-quality polyethylene glycol, polyethylene glycol derivatives, block copolymers, anti-diabetic drug side chains, lipid excipients (ingredients for mRNA delivery system), ADC and ProTAC Linker, etc. Please contact us at sales@sinopeg.com #BIO

Welcome to visit us at SINOPEG's Booth #137 at Tides USA 2022, Boston, USA from 9th to 12th May. SINOPEG has a high-level team with strong technical reserve to research, develop and produce high-quality polyethylene glycol, polyethylene glycol derivatives, block copolymers, anti-diabetic drug side chains, lipid excipients (ingredients for mRNA delivery system), ADC and ProTAC Linker, etc. Please coutact us at sales@sinopeg.com

Welcome to visit us at SINOPEG's Booth #137 at Tides USA 2022, Boston, USA from 9th to 12th May.

Welcome to visit us at SINOPEG's Booth #2351 at 2022 BIO International Convention, San Diego, CA, the USA from 13th to 16th June. SINOPEG is a dynamic science company with professional R&D, Manufacturing and Sales capability. The company is mainly engaged in drug delivery system (DDS) and new medical materials business. Founded in 2011, SINOPEG has a high-level team with strong technical reserve to research, develop and produce high-quality polyethylene glycol, polyethylene glycol derivatives, block copolymers, anti-diabetic drug side chains, lipid excipients (ingredients for mRNA delivery system), ADC and ProTAC Linker, etc. SINOPEG has a technical team led by overseas returned doctors and foreign experts, established good cooperation relations with well-known universities and research institutes in China, such as Xiamen University, Fudan University and the Institute of Chemistry of Chinese Academy of Sciences. The company has the first-class technology development strength, provides services including the reaction, purification, separation and end product analysis and others according to customer needs. SINOPEG holds 24 IP, 19 pending IP, and 6 DMFs that meet FDA requirements. The company has ISO13485 certification. The laboratory and production workshop are designed and built in accordance with the cGMP standard of FDA. We follow the requirements of ICH-Q7A to organize production at scale, to provide high quality polyethylene glycol derivatives products and services to customers globally.

As COVID-19 continuing in 2021, it is necessary to take preventive measures, to accelerate the speed of research and development of COVID-19 vaccines and drugs, to advocate the innovation of new vaccines technologies, and to build the strength to win this epidemic. VacCon 2022, focus on technical breakthrough of the novel vaccines in post COVID-19 era. It will invite 60+ government regulatory experts, scientists and leading entrepreneurs who specialize in vaccine/ neutralizing antibody/ small molecule novel coronavirus drugs. The theme is "Focusing on technical breakthrough of the novel vaccines in post COVID-19 era", which will discuss the latest clinical development, before project approval and R&D in COVID-19 vaccine and drugs, and the leading practice of innovation and process development of mRNA/recombinant protein/adenovirus vector vaccine under different technical paths. SINOPEG, as one of the few companies in China to achieve the commercial production of lipid nanoparticles delivery materials, also attracted a lot of friends to communicate with us at the booth.

LNP delivery system The major COVID-19 vaccine technology routes currently under development worldwide include inactivated vaccines, mRNA vaccines, adenovirus vaccines and recombinant protein vaccines. As a new vaccine technology in the market, mRNA vaccine is also one of the most important COVID-19 vaccines in the world at present. As a new technology, why can mRNA vaccine be widely administered around the world? One important reason is that it has a very high effective protection rate. The two available mRNA vaccines have an effective protection rate of more than 90%, and BioNTech's mRNA vaccine, produced in collaboration with Pfizer, has an effective protection rate of 95%.Since vaccination began, the daily positive rate in the United States has dropped from 20 percent to 1 to 2 percent. MRNA transmits the genetic information for producing an antigen to the cells that make the protein. These cells then present the antigen to their surfaces, triggering the specific immune response needed. Eventually, when a virus invades, the immune system recognizes specific antigens and quickly and specifically attacks the virus to prevent infection. MRNA technology can not only be used as a preventive vaccine to prevent the spread of infectious diseases, but also as a therapeutic drug to treat some serious diseases, such as cancer and AIDS, due to its ability to spontaneously stimulate human immunity. MRNA has large molecular weight, strong hydrophilicity and high biological activity, but its single chain structure makes it extremely unstable and easy to be degraded, and delivery through the membrane with negative charge on the surface is also difficult. MRNA must enter the cell to encode antibodies, and the enzyme degradation and cell membrane barrier in the process of entering the cell are the biggest challenges that affect its delivery efficiency and transfection efficiency. Special modification or package delivery systems are required to achieve intracellular expression of mRNA. At present, Lipid nanoparticle (LNP) is commonly used as a carrier to deliver mRNA .Lipid nanoparticles mainly contain four components: ionizable lipids, neutral helper lipids, cholesterol, and PEGylated lipid. The neutral helper lipids are usually saturated phospholipids, which support the formation of the lamellar lipid bilayer and stabilize its structure arrangement. Cholesterol had strong membrane fusion, which promoted the intracellular uptake of mRNA and cytoplasmic entry. Pegylated lipids are located on the surface of lipid nanoparticles, improving their hydrophilicity and avoiding rapid removal by the immune system, preventing particle aggregation and increasing stability. The most critical excipients are ionizable cationic lipids, which are decisive factors in the efficiency of mRNA delivery and transfection. Mechanism of LNP mRNA delivery: before entering cells, cationic lipids can realize electrostatic complexation with negatively charged mRNA molecules to form complex...