My journey with PEGylation

Die Medizin wird sich in den kommenden Jahren weiter personalisieren. Entscheidende Grundlage für eine individualisierte Diagnostik und Therapie ist der Zugriff auf alle relevanten Patientendaten in Form einer elektronischen Patientenakte (ePA), gepaart mit einem digitalen Instrumentarium, um die richtigen therapeutischen Schlüsse aus der vorhandenen Datenflut zu ziehen. Entsprechend wird die Digitalisierung der Gesundheitsversorgung von drei zentralen Entwicklungen angetrieben: 1) besseres Verständnis der biologischen Lebensgrundlagen durch den breiteren Einsatz von DNA-Sequenzierungen, 2) technologische Quantensprünge bei Computing und Datenspeicherung, gepaart mit dem ubiquitären Zugang zu Daten über Smartphones sowie 3) deutlich gestiegenes Souveränitätsbedürfnis der Patienten auf der Basis zunehmender Transparenz und digitaler Kommunikation. Die Digitalisierung wird somit Mittel zum Zweck einer verbesserten Gesundheitsversorgung. Dabei ist die Erhaltung der menschlichen Komponente entscheidend. Erst eine „humane Digitalisierung“, in der der Nutzen für Patienten sowie für Behandelnde und Pflegende im Mittelpunkt steht, wird die vorhandenen Potenziale auch heben.

The treatment of chronic hepatitis C is based on the combination of pegylated interferon and ribavirin. However, non response is usually observed in 31-35% of cases. The therapeutic failure can be due to co-morbidities, especially overweight associated with insulin resistance and alcohol consumption. The compliance is very important in particular for ribavirin taking in the first weeks of treatment. The using of hematopoietic growth factors especially epoietin which should be proposed in order to maintain the same dose of ribavirin. Recently a genetic polymorphism has been identified located on chromosome 19 near the interleukine-28B gene encoding interferon-λ-3, that is associated with a two-fold difference in response to treatment with pegylated interferon and ribavirin in patients infected with HCV genotype 1. The re-treatment by the same schedule of pegylated interferon and ribavirin leads to a sustained virological response in less than 10% of cases. An increasing dose of pegylated interferon is not a good option. Increasing the dose of ribavirin remained to test in therapeutic trials. A maintenance therapy by pegylated interferon alone is usually associated with an improvement of necro-inflammatory lesions but the gain in term of fibrosis rate is very low. A new therapeutic approach is the using of antiprotease or antipolymerase inhibitors in combination with pegylated interferon and ribavirin.

Asparaginase (ASP) is an effective chemotherapy agent extensively used in children with acute lymphocytic leukemia (ALL). There has been a recent interest in using ASP in adults with ALL, particularly the less toxic pegylated (PEG) formulation. Hypertriglyceridemia (HTG) is a rare complication of PEG-ASP therapy. We report two cases of obese patients who developed severe HTG after receiving PEG for ALL. Both patients were incidentally found to have severe HTG (TG of 4,330 and 4,420 mg/dL). In both patients, there was no personal or family history of dyslipidemia or hypothyroidism. There was no evidence of pancreatitis or skin manifestations of HTG. Both patients were treated with PEG cessation, low-fat diet and pharmacotherapy. Both patients were re-challenged with PEG, with subsequent increase in TG but no associated complications. TG returned to baseline after discontinuing PEG and while on therapy for HTG. A literature review of PEG-induced HTG in adults demonstrated similar results: asymptomatic presentation despite very severe HTG. HTG is a rare but clinically important adverse effect of PEG. Underlying obesity and/or diabetes may represent risk factors. Clinicians should monitor TG levels during PEG therapy to avoid TG-induced pancreatitis.

Objective Human aortic valve interstitial cells (HAVICs) were seeded onto decellularized valves in order to fabricate tissue engineering heart valves in a bioreactor system.Methods Decellularized valves were cross-linked by polyethylene glycol.PEGylated decellularized valves were covalently modified by GRGDSPC peptides.The modified effect of GRGDSPC peptides was determined by using immunofluorescence.HAVICs were seeded onto PEGylated decellularized valves modified by GRGDSPC peptides.Then the valves were sutured into a bioreactor system.Cell adhesion was tested respectively after 2,4 and 8 h.After 10 days of culture,hematoxylin-eosin staining,scanning electron microscopy and DNA content test were performed.Results Immunofluorescence showed that PEGylated decellularized valves could be effectively modified by GRGDSPC peptides through covalent bonding.As compared with decellularized valves,PEGylated decellularized valves modified by GRGDSPC peptides significantly promoted the adhesion of HAVICs.Number of adherent cells after 2,4 and 8 h was respectively (4.98 ±0.46) × 107/L vs.(3.35 ±0.15) ×107/L,(5.71 ±0.29)× 107/L vs.(3.55 ±0.18) ×107/L,(5.97 ±0.45) ×107/L vs.(3.62 ±0.18) × 107/L,P ＜0.05.The DNA content of PEGylated decellularized valves modified by GRGDSPC peptides was significantly higher than that of decellularized valves [(25.98 ± 2.45) μg/valve vs.(19.61 ±1.94) μg/valve,P ＜ 0.05].Conclusion Modification of PEGylated decellutarized valves by GRGDSPC peptides can promote the adhesion of cells seeded on valves in a bioreactor system. Key words: Decellularized valves; Polyethylene glycol; Bioreactor; Adhesion

Objective To investigate the modified methods of polyethylene glycol (PEG) to pol-ypeptide YIGSR ,and the degradation of PEG-YIGSR in serum of SD rats in vitro ,and the adhesion inhibi-tory potential of PEG-YIGSR on the hepatocellular carcinoma cell line MHCC97H cells. Methods YIGSR was reacted to the mPEGALD10000 synthesizing the pegylated YIGSR conjugate (PEG-YIGSR) under the certain conditions (pH 4 to 6, PEG: YIGSR 1:1 to 10:1). The couple rate of pegylation and the degrada-tion speed of PEG-YIGSR in SD rat serum were detected by using the LC-MS method in vitro. The hepato-cellular carcinoma cell line MHCC97H cells were treated with PEG-YIGSR, and then the cell adhesion po-tential was tested by in vitro cell-matrix adhesion test. Results The couple rate of pegylation was up to 99.9% in different pH values ,and it was increased with the incresse of PEG modifier dose. PEG-YIGSR markedly inhibited cell adhesion to laminin (LN) up to 19.5% in a dose-and time-dependent manner. The degradation speed of PEG-YIGSR in SD rat serum was slower than that of YIGSR in vitro [AUC was riginal inhibition potential on MHCC97H cells adhesion to LN. The action time of PEG-YIGSR would ex-tend due to its slow degradation in SD rat serum. Key words: Carcinoma; hepatocellular; Adhesion; Polyethylene glycol; Polypeptide

To construct PEGylated trichosanthin (TCS) mutein and analyze its bioactivities, immunogenicity, acute toxicity, and pharmacokinetics. The potential antigenic determinant site YFF81-83 in the molecule of TCS was selected to undergo site-directed mutagenesis. Thus, a TCS mutein named TCS(YFF81-83ACS) was constructed and expressed in Escherichia coli of the line BL21 (DE3). Wild TCS (wTCS), TCSY(FF81-83ACS), and PEGylated TCS(YFF81-83ACS) (PEG- TCS(YFF81-83ACS)) of different concentrations were incubated with the supercoiled plasmid pUC19 to detect the DNAse activity, mixed with rabbit reticulocyte lysate to detect the ribosome inactivation activity, subcutaneously injected into 6 mice respectively to measure the serum IgG and IgE levels, intravenously injected into mice to observe the toxicity, and intravenously injected into SD rats to observe its -plasma half-life. The DNAse activity of the PEG-TCS(YFF81-83ACS) was similar to that of the wTCS. The ribosome inactivation activity of the PEG-TCS(YFF81-83ACS) was 1/9-1/8 of that of the wTCS (P < 0.05). The serum IgE and IgG levels of the PEG-TCS(YFF81-83ACS) were both significantly lower than those of the wTCS (both P < 0.05). The LD50 of the PEG-TCS(YFF81-83ACS) was 1.8 times that of the wTCS (P < 0.05). The mean residence time and plasma half-life of the PEG-TCS(YFF81-83ACS) were significantly increased and its plasma clearance was significantly decreased (all P < 0.05). Site-directed mutagenesis and PEGylation of TCS provide a new approach for reconstructing TCS.

Objective To evaluate the efficacy of pegylated interferon α-2a and entecavir (ETV) combination therapy for patients with HBeAg positive chronic hepatitis B(CHB). Methods Fifty eight HBeAg positive CHB patients were assigned to two groups: 29 patients received ETV 0.5 mg daily for 72 weeks (ETV group) and 29 patients received ETV and pegylated interferon α-2a 180 μg weekly for 48 weeks followed by ETV alone for 24 weeks (combination group). Serum samples were collected from all patients every 12 weeks for assessment of biochemical, virological and serological responses to treatment. Results Fifty four patients completed the 72-week study, including 28 in ETV group and 26 in combination group. There were no significant differences in week 24, week 48 and week 72 of ALT normalization [72%(21/29) vs. 93%(27/29), χ2=2.104; 90%(26/29) vs. 97%(28/29), χ2=0.269; 90%(26/29) vs. 97%(28/29), χ2=0.269], HBV DNA undetectable rate [31%(8/26) vs. 46%(13/28), χ2=1.391; 62%(16/26) vs. 57%(16/28), χ2=0.108; 77%(20/26) vs. 75%(21/28), χ2=0.027], HBeAg loss rate[12%(3/26) vs. 25%(7/28), χ2=0.850; 31%(8/26) vs. 32%(9/28), χ2=0.012; 46%(12/26) vs. 36%(10/28), χ2=0.609] and HBsAg levels(log10 IU/ml)(3.63±0.45 vs. 3.36±1.18, t=-1.066; 3.45±0.43 vs. 3.23±1.15, t=-0.915; 3.36±0.58 vs. 2.88± 1.28, t=-1.762)between two regimens (all P>0.05). Among 58 patients, 15 were HBeAg and anti-HBe double-positive (26%)and 43 were HBeAg mono-positive patients. The baseline HBV DNA level [(5.07±1.50) vs. (6.40±1.47) log10 IU/ml, t=2.858, P<0.05] and HBeAg titer [14(4-45) vs. 732(296-1 012)S/CO, Z=-5.031, P=0.05] in double-positive patients were lower than those in mono-positive patients. The HBV DNA undetectable rate of double-positive patients was significantly higher than that of mono-positive patients in 24 weeks [10/15 vs. 26%(10/39), χ2=7.819, P<0.05] and 72 weeks [15/15 vs. 69%(27/39), χ2=4.287, P=0.05]. The HBeAg loss rate of double-positive patients was higher than that of mono-positive patients in 12 weeks [6/15 vs. 10%(4/39), χ2=4.533, P=0.05] and 48 weeks [9/15 vs. 26%(10/39), χ2=5.608, P=0.018]. This tendency was more significant in the combination therapy group, but the difference was not statistically significant. (5/6 vs. 4/9, P=0.065). Conclusions Compared with Entecavir monotherapy, entecavir combined with interferon may not improve the therapeutic effect in HBeAg positive chronic hepatitis B patients. However, the therapeutic response of HBeAg /anti-HBe double-positive patients may better than that of HBeAg mono-positive patients. Key words: Hepatitis B, chronic; Peginterferon Alfa-2a; Entecavir; Drug therapy, combined

Objective To evaluate the influcing factors on the efficacy of combined treatment of pegylated interferon-α (PegIFN) and ribavirin (RBV) in patients with chronic hepatitis C. Methods The clinical data of 148 HCV-infected patients who were treated with PegIFN and RBV in Central Hospital of Baoji from January 2008 to December 2011 were analyzed, retrospectively. The sustained virological response 24 weeks (SVR24), early virological (EVR), treatment virological response (ETR), 12 weeks of sustained virological response (SVR12), recurrence, invalid response, virological breakthrough were used to evaluate the curative effect, and influencing factors of curative effect were analyzed by Logistic regression. Results Among the 148 patients with HCV infection, 12 (8.1%) cases were lost. Among the 136 patients with EVR, 128 (94.1%) patients experienced EVR, 118 cases (86.8%) experienced ETR, 114 (83.8%) patients experienced SVR12, 112 (82.4%) patients experienced SVR24, 8 (5.9%) patients were invalid response, 6 (4.4%) patients experienced recurrence and 4 (2.9%) patients had virological breakthrough. HCV RNA, HCV genotype and UA were all influencing factors on the efficacy of SVR24 in HCV infected patients (all P < 0.05). Conclusions Treatment of PegIFN combined with RBV has significant effect on HCV infection. HCV genotype 2/3, lower HCV RNA level and uric acid were associated with HCV SVR. Key words: Hepatitis C; Pegylated interferon; Ribavirin; Uric acid

Objective To evaluate the influencing factors of chronic hepatitis C relatpse treated with pegylated interferon alpha-2a and ribavirin in post-treatment,and study on relatpse time.Methods 92 chronic hepatitis C patients treated with pegylated interferon alpha-2a and ribavirin relapsed in post-treatment.A retrospective study was designed to analyze the influencing factors of chronic hepatitis C relatpse.Results 81 patients receives the sustained virological response(SVR),11 patients relapsed.The rapid virological response and complete early virological response of SVR patients were significantly higher than relapsed patients(P ＜0.05 ; P ＜0.001).11 relapsed patients occured within 24 weeks after stopped therapy,8 relapsed patients occured within 12 weeks.Conclusions The sooner of virus response to pgylated interferon alpha-2a plus ribavirin therapy,the lower of the relapse rate. Key words: Chronic hepatitis C ; Relapse ; Pegylated interferon alpha-2a; Ribavirin

Doxorubicin is a widely used anticancer agent as a first-line treatment for various tumor types, including sarcomas. Its use is hampered by adverse events, among which is the risk of dose dependence. The potential cardiotoxicity, which increases with higher doses, poses a significant challenge to its safe and effective application. To try to overcome these undesired effects, encapsulation of doxorubicin in liposomes has been proposed. Caelyx and Myocet are different formulations of pegylated (PLD) and non-pegylated liposomal doxorubicin (NPLD), respectively. Both PLD and NPLD have shown similar activity compared with free drugs but with reduced cardiotoxicity. While the hand-foot syndrome exhibits a high occurrence among patients treated with PLD, its frequency is notably reduced in those receiving NPLD. In this prospective, multicenter, one-stage, single-arm phase II trial, we assessed the combination of NPLD and ifosfamide as first-line treatment for advanced/metastatic soft tissue sarcoma (STS). Patients received six cycles of NPLD (50 mg/m2) on day 1 along with ifosfamide (3000 mg/m2 on days 1, 2, and 3 with equidose MESNA) administered every 3 weeks. The overall response rate, yielding 40% (95% CI: 0.29-0.51), resulted in statistical significance; the disease control rate stood at 81% (95% CI: 0.73-0.90), while only 16% (95% CI: 0.08-0.24) of patients experienced a progressive disease. These findings indicate that the combination of NPLD and ifosfamide yields a statistically significant response rate in advanced/metastatic STS with limited toxicity.

Supplementary Data. A document containing four supplementary figures and one supplementary table. UV-vis absorbance readings; zeta potential measurements of bare and PEGylated AuNPs; and additional cellular TEM images. (PDF 4592Â kb)

XRD patterns of bare Fe3O4 nanoparticles (SPION), PEGylated Fe3O4 nanoparticles (PEG-SPION) and pure PEG powder. Figure S2. (a-e) Bright field HRTEM images of PEG-SPION showing Fe3O4 cores fully coated with PEG. Figure S3. Zeta potential measurements showing the isoelectric point (IEP) of SPION and SPION stabilized with PEG (3350). Figure S4. DLS measurements of SPION and PEG-SPION dispersed in deionized water. Figure S5. A proposed mechanism of dipole cationic binding of ether group of PEG to Fe3O4 surface and hydration process of PEG for aqueous dispersibility. (DOCX 71194 kb)

Many patients with hepatitis C virus (HCV) infections do not respond to treatment with standard interferon (IFN) regimens. Pegylated interferon is more

Objective To evaluate the efficacy and side effects of priming regimen with pegylated recombinant human granulocyte colony-stimulating factor (PEG-rhG-CSF) in the treatment of initial treatment elderly patients with acute myeloid leukemia (AML). Methods Thirty-five elderly patients with early-stage AML (non-M3) who received pre-excitation chemotherapy in Yancheng Third People's Hospital from February 2015 to January 2019 were retrospectively analyzed. According to the different granulocyte colony-stimulating factor (G-CSF) in the chemotherapy regimen, 15 cases were in PEG-rhG-CSF group, 6 mg PEG-rhG-CSF was used alone on day 0 by subcutaneous injection; 20 cases were in recombinant human granulocyte colony-stimulating factor (rhG-CSF) group, 200 μg/m2 rhG-CSF was used per day from day 0 to day 13 by subcutaneous injection, rhG-CSF was suspended or continued according to the number of white blood cells. In addition, both groups were given priming regimen with cytarabine and arubicin, or cytarabine and harringtonine. The efficacy and adverse reactions of the two groups were compared. Results In the PEG-rhG-CSF group, there were 5 cases of complete remission, 6 cases of partial remission, 4 cases of non-remission, and 11 cases were effective. In the rhG-CSF group, there were 8 cases of complete remission, 7 cases of partial remission, 5 cases of non-remission, and 15 cases were effective. There was no significant difference in the efficacy between the two groups (χ 2= 0.012, P= 0.911). In terms of adverse reactions, the incidence of infectious fever, bone pain, duration of neutropenia, and duration of thrombocytopenia were not statistically significant (all P > 0.05). Conclusions In the pre-excitation chemotherapy for AML, the clinical efficacy and adverse effects of PEG-rhG-CSF are similar to rhG-CSF. However, the use of PEG-rhG-CSF can simplify the operation and reduce the pain and risk of local infection during chemotherapy. Key words: Leukemia, myeloid, acute; Polyethylene glycols; Granulocyte colony-stimulating factor; Priming regimen

Proteins have gained an important role in clinical practice, and they are the treatment of choice or even the only therapy for several pathologies. Unfortunately, their great potential is often hampered by relevant shortcomings such as immunogenicity and fast body clearance. Polymer conjugation, especially with polyethylene glycol (PEG), has emerged as a suitable drug delivery solution to address these drawbacks. Furthermore, this technology has been found to be a powerful approach to increase the general therapeutic efficacy of biomolecules. After the first PEG-protein derivatives were released, it was clear that a wider exploitation of PEGylation could be reached only through thorough development of the methods of conjugation. At the moment, different PEG coupling strategies and PEG polymers are available. The research in this field is very active and a large effort has been focused on developing releasable PEGs, which are polymers able to release the conjugated protein. This feature enables the recovery of the protein activity that is commonly reduced after polymer coupling.