Kraft pulp enzymatic hydrolysis is a promising method of woody biomass bioconversion. The influence of composition and structure of kraft fibers on their hydrolysis efficiency was evaluated while using four substrates, unbleached hardwood pulp (UHP), unbleached softwood pulp (USP), bleached hardwood pulp (BHP), and bleached softwood pulp (BSP). Hydrolysis was carried out with Penicillium verruculosum enzyme complex at a dosage of 10 filter paper units (FPU)/g pulp. The changes in fiber morphology and structure were visualized while using optical and electron microscopy. Fiber cutting and swelling and quick xylan destruction were the main processes at the beginning of hydrolysis. The negative effect of lignin content was more pronounced for USP. Drying decreased the sugar yield of dissolved hydrolysis products for all kraft pulps. Fiber morphology, different xylan and mannan content, and hemicelluloses localization in kraft fibers deeply affected the hydrolyzability of bleached pulps. The introduction of additional xylobiase, mannanase, and cellobiohydrolase activities to enzyme mixture will further improve the hydrolysis of bleached pulps. A high efficiency of never-dried bleached pulp bioconversion was shown. At 10% substrate concentration, hydrolysates with more than 50 g/L sugar concentration were obtained. The bioconversion of never-dried BHP and BSP could be integrated into working kraft pulp mills.
Colorectal cancer is the third most common type of cancer in men and the second in women worldwide. The data demonstrate the increase in the annual incidence of colorectal cancer, but still the significant number of patients is detected having late-stage cancer. Regorafenib is an oral multi-kinase inhibitor that targets kinases VEGF1, VEGF2, VEGF3, PDGFR, and FGFR involved in the regulation of tumor angiogenesis, and KIT, RET, RAF-1, BRAF involved in oncogenesis. The application of regorafenib has shown statistically significant increase of progression-free survival and overall survival, thus regorafenib been approved for the treatment of metastatic colorectal cancer, associated with resistance to fluoropyrimidine, oxaliplatin or irinotecan-based therapy in combination with the VEGR inhibitor and anti-EGFR-antibodies in patients with wild type KRAS gene. The article deals with the results of major studies carried out to explore the characteristics and efficacy and safety evaluation of regorafenib. We have analyzed in the review the results of recent studies on changes in indicators of overall survival, progression-free survival, and the efficacy of regorafenib therapy, safety and objective response.
Colorectal cancer (CRC) is one of the leading cancers in terms of prevalence and mortality. Almost 1/4 of patients with CRC have metastases at the initial presentation. The survival rate of this group of patients remains low. With the onset of the COVID-19 pandemic, cancer patients have faced difficulties in getting diagnosis or treatment, which could potentially lead to an increase in late-stage tumors and mortality. This situation required changes in approaches to the treatment of cancer patients, such as replacing drugs with tablet forms, schemes with long intervals, and much more. It is known that about 50% of patients with metastatic colorectal cancer survive in satisfactory condition until the 3rd line drug therapy or longer. One of the main drugs for this category of patients is regorafenib, which, thanks to the tablet formulation, has become especially important in the COVID-19 pandemic. In numerous clinical studies, the drug showed an increase in patient overall survival and good safety profile. In addition, there is growing evidence of the effect of regorafenib on tumor sensitivity to treatment with platinum drugs, irinotecan, and EGFR inhibitors.
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