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1.
JAMA Surg ; 152(10): 960-966, 2017 Oct 01.
Article in English | MEDLINE | ID: mdl-28658482

ABSTRACT

IMPORTANCE: The expansion of Medicaid eligibility under the Affordable Care Act is a state-level decision that affects how patients with traumatic injury (trauma patients) interact with locoregional health care systems. Washington, DC; Maryland; and Virginia represent 3 unique payer systems with liberal, moderate, and no Medicaid expansion, respectively, under the Affordable Care Act. Characterizing the association of Medicaid expansion with hospitalization after injury is vital in the disposition planning for these patients. OBJECTIVE: To determine the association between expanded Medicaid eligibility under the Affordable Care Act and duration of hospitalization after injury. DESIGN, SETTING, AND PARTICIPANTS: This retrospective cohort study included patients admitted from Virginia, Maryland, and Washington, DC, to a single level I trauma center. Data were collected from January 1, 2013, through March 6, 2016, in Virginia and Washington, DC, and from May 1, 2013, through March 6, 2016, in Maryland. All patients with Medicare or Medicaid coverage and all uninsured patients were included. Patients with private insurance, patients with severe head or pelvic injuries, and those who died during hospitalization were excluded. MAIN OUTCOMES AND MEASURES: Hospital length of stay (LOS) and whether its association with patient insurance status varied by state of residence. RESULTS: A total of 2314 patients (1541 men [66.6%] and 773 women [33.4%]; mean [SD] age, 52.9 [22.8] years) were enrolled in the study. The uninsured rate in the Washington, DC, cohort (190 of 1699 [11.2%]) was significantly lower compared with rates in the Virginia (141 of 296 [47.6%]) or the Maryland (106 of 319 [33.2%]) cohort (P < .001). On multivariate regression controlling for injury severity and demographic variables, the difference in LOS for Medicaid vs non-Medicaid recipients varied significantly by state. For Medicaid recipients, mean LOS in Washington, DC, was significantly shorter (2.57 days; 95% CI, 2.36-2.79 days) than in Maryland (3.51 days; 95% CI, 2.81-4.38 days; P = .02) or Virginia (3.9 days; 95% CI, 2.79-5.45 days; P = .05). CONCLUSIONS AND RELEVANCE: Expanded Medicaid eligibility is associated with shorter hospital LOS in mildly injured Medicaid recipients.


Subject(s)
Insurance Coverage , Length of Stay , Medicaid , Patient Protection and Affordable Care Act , Wounds and Injuries/therapy , Adult , Aged , District of Columbia , Female , Humans , Male , Maryland , Middle Aged , Retrospective Studies , United States , Virginia , Wounds and Injuries/economics
2.
AIDS Res Hum Retroviruses ; 32(5): 456-62, 2016 May.
Article in English | MEDLINE | ID: mdl-26559180

ABSTRACT

Chronic hepatitis C virus (HCV) infection is associated with lower serum concentration of low-density lipoprotein (LDL-C), the primary cholesterol metabolite targeted pharmaceutically to modulate cardiovascular risk. Chronic infection with human immunodeficiency virus (HIV) and treatment with antiretrovirals (ARVs) are associated with dyslipidemia and increased risk of cardiovascular disease. In subjects coinfected with HIV and HCV, lipid abnormalities associated with either infection alone are often attenuated. Treatment of chronic HCV infection in HIV/HCV-coinfected subjects is now possible with interferon (IFN)-free regimens composed of directly acting antivirals (DAAs). We previously observed a marked increase in serum LDL-C in HCV-monoinfected subjects treated with sofosbuvir and ribavirin (SOF/RBV) that correlated with viral decline in serum, suggesting a direct influence of HCV clearance on serum cholesterol. In the present study, we assessed longitudinal changes in cholesterol in HIV/HCV-coinfected subjects during treatment of HCV genotype-1 (GT1) infection with combination DAA therapy. We report a rapid increase in LDL-C and LDL particle size by week 2 of treatment that was sustained during and after treatment in HIV/HCV-coinfected subjects. No change in serum LDL-C was observed at day 3 of treatment, in spite of a marked reduction in serum HCV viral load, suggesting LDL-C increases do not directly reflect HCV clearance as measured in peripheral blood. After effective DAA therapy for HCV, an increase in LDL should be anticipated in HIV/HCV-coinfected subjects.


Subject(s)
Antiviral Agents/therapeutic use , Cholesterol, LDL/blood , Coinfection/drug therapy , Dyslipidemias/chemically induced , HIV Infections/drug therapy , HIV-1/drug effects , Hepacivirus/drug effects , Hepatitis C, Chronic/drug therapy , Antiviral Agents/adverse effects , Benzimidazoles/adverse effects , Benzimidazoles/therapeutic use , Cardiovascular Diseases , Coinfection/virology , Drug Therapy, Combination , Dyslipidemias/blood , Female , Fluorenes/adverse effects , Fluorenes/therapeutic use , Furans/adverse effects , Furans/therapeutic use , Humans , Male , Middle Aged , Prospective Studies , Quinolines/adverse effects , Quinolines/therapeutic use , Ribavirin/adverse effects , Ribavirin/therapeutic use , Sofosbuvir/adverse effects , Sofosbuvir/therapeutic use , Thiophenes/adverse effects , Thiophenes/therapeutic use , Uridine Monophosphate/adverse effects , Uridine Monophosphate/analogs & derivatives , Uridine Monophosphate/therapeutic use
3.
Hepatol Int ; 10(2): 310-9, 2016 Mar.
Article in English | MEDLINE | ID: mdl-26612014

ABSTRACT

BACKGROUND: As treatment for chronic hepatitis C (HCV) virus has evolved to all-oral, interferon-free directly acting antiviral (DAA) therapy, the impact of these improvements on patient adherence has not been described. METHODS: Medication adherence was measured in 60 HCV, genotype-1, treatment-naïve participants enrolled in a phase 2a clinical trial at the National Institutes of Health and community clinics. Participants received either ledipasvir/sofosbuvir (LDV/SOF) (90 mg/400 mg) (one pill) daily for 12 weeks, LDV/SOF + GS-9451 (80 mg/day) (two pills) daily for 6 weeks, or LDV/SOF + GS-9669 (500 mg twice daily; three pills, two in the morning, one in the evening) for 6 weeks. Adherence was measured using medication event monitoring system (MEMS) caps, pill counts and patient report. RESULTS: Overall adherence to DAAs was high. Adherence declined over the course of the 12-week treatment (p = 0.04). While controlled psychiatric disease or symptoms of depression did not influence adherence, recent drug use was a risk factor for non-adherence to 12-week (p = 0.01), but not 6-week regimens. Adherence as measured by MEMS was lower than by patient report. CONCLUSIONS: Adherence to short courses of DAA therapy with 1-3 pills a day was excellent in an urban population with multiple risk factors for non-adherence.


Subject(s)
Antiviral Agents/administration & dosage , Hepatitis C, Chronic/drug therapy , Medication Adherence , Administration, Oral , Drug Administration Schedule , Drug Therapy, Combination , Female , Humans , Male , Middle Aged , Treatment Outcome , Urban Population
4.
AIDS ; 30(2): 261-6, 2016 Jan.
Article in English | MEDLINE | ID: mdl-26691547

ABSTRACT

OBJECTIVE: As the treatment of hepatitis C virus (HCV) infection has evolved to directly acting antiviral agents, the impact of these directly acting antiviral-only regimens on improving adherence to HCV treatment in HIV/HCV coinfected populations has not been evaluated. The study compared adherence to ledipasvir/sofosbuvir (LDV/SOF) in HCV monoinfected and HIV/HCV coinfected individuals. DESIGN: Adherence was measured from participants in two phase 2 open-label studies (NCT01805882 and NCT01878799). METHODS: HCV treatment-naive, genotype 1 study individuals [HCV monoinfected participants (N = 20) and HIV/HCV coinfected participants, antiretroviral untreated (N = 13) or on combination antiretroviral therapy (N = 37)] were treated with LDV (90 mg) and SOF (400 mg) administered as one tablet once daily for 12 weeks. Adherence was measured using three tools: medication event monitoring system cap, pill count, and patient report. RESULTS: Participants were predominately African American (83%) and male (73%), with a median age of 59 years. Participants had prompt HCV viral load decline and high adherence rates (97 ±â€Š0.5% by medication event monitoring system). Participant adherence decreased significantly from early (baseline week 4) as compared with late (weeks 8-12) in therapy in all three groups - HCV monoinfected (P = 0.01), HIV/HCV antiretroviral untreated (P = 0.02), and HIV/HCV antiretroviral treated participants (P = 0.01). CONCLUSION: Adherence to LDV/SOF in this urban population was high and comparable between HCV monoinfected and HIV/HCV coinfected participants regardless of antiretroviral use.


Subject(s)
Antiviral Agents/administration & dosage , Benzimidazoles/administration & dosage , Coinfection/drug therapy , Fluorenes/administration & dosage , HIV Infections/complications , Hepatitis C, Chronic/drug therapy , Medication Adherence , Sofosbuvir/administration & dosage , Female , Hepatitis C, Chronic/complications , Humans , Male , Middle Aged , Urban Population
6.
JAMA ; 313(12): 1232-9, 2015.
Article in English | MEDLINE | ID: mdl-25706232

ABSTRACT

IMPORTANCE: There is an unmet need for interferon- and ribavirin-free treatment for chronic hepatitis C virus (HCV) infection in patients co-infected with human immunodeficiency virus (HIV). OBJECTIVE: To evaluate the rates of sustained virologic response (SVR) and adverse events in previously untreated patients with HCV genotype 1 and HIV co-infection following a 12-week treatment of the fixed-dose combination of ledipasvir and sofosbuvir. DESIGN, SETTING, AND PARTICIPANTS: Open-label, single-center, phase 2b pilot study of previously untreated, noncirrhotic patients with HCV genotype 1 and HIV co-infection conducted at the Clinical Research Center of the National Institutes of Health, Bethesda, Maryland, from June 2013 to September 2014. Patients included those receiving antiretroviral therapy with HIV RNA values of 50 copies/mL or fewer and a CD4 T-lymphocyte count of 100 cells/mL or greater or patients with untreated HIV infection with a CD4 T-lymphocyte count of 500 cells/mL or greater. Serial measurements of safety parameters, virologic and host immune correlates, and adherence were performed. INTERVENTIONS: Fifty patients with HCV genotype 1 never before treated for HCV were prescribed a fixed-dose combination of ledipasvir (90 mg) and sofosbuvir (400 mg) once daily for 12 weeks. MAIN OUTCOMES AND MEASURES: The primary study outcome was the proportion of patients with sustained viral response (plasma HCV RNA level <12 IU/mL) 12 weeks after end of treatment. RESULTS: Forty-nine of 50 participants (98% [95% CI, 89% to 100%]) achieved SVR 12 weeks after end of treatment, whereas 1 patient experienced relapse at week 4 following treatment. In the patient with relapse, deep sequencing revealed a resistance associated mutation in the NS5A region conferring resistance to NS5A inhibitors, such as ledipasvir. The most common adverse events were nasal congestion (16% of patients) and myalgia (14%). There were no discontinuations or serious adverse events attributable to study drug. CONCLUSIONS AND RELEVANCE: In this open-label, uncontrolled, pilot study enrolling patients co-infected with HCV genotype 1 and HIV, administration of an oral combination of ledipasvir and sofosbuvir for 12 weeks was associated with high rates of SVR after treatment completion. Larger studies that also include patients with cirrhosis and lower CD4 T-cell counts are required to understand if the results of this study generalize to all patients co-infected with HCV and HIV. TRIAL REGISTRATION: clinicaltrials.gov Identifier:NCT01878799.


Subject(s)
Antiviral Agents/therapeutic use , Benzimidazoles/therapeutic use , Fluorenes/therapeutic use , HIV Infections/drug therapy , Hepacivirus/genetics , Hepatitis C, Chronic/drug therapy , Uridine Monophosphate/analogs & derivatives , Administration, Oral , Adult , Benzimidazoles/adverse effects , Coinfection , Drug Therapy, Combination , Female , Fluorenes/adverse effects , Genotype , Humans , Male , Middle Aged , Myalgia/chemically induced , RNA, Viral , Sofosbuvir , Treatment Outcome , Uridine Monophosphate/adverse effects , Uridine Monophosphate/therapeutic use , Viral Load
7.
Lancet ; 385(9973): 1107-13, 2015 Mar 21.
Article in English | MEDLINE | ID: mdl-25591505

ABSTRACT

BACKGROUND: Direct-acting antiviral drugs have a high cure rate and favourable tolerability for patients with hepatitis C virus (HCV). Shorter courses could improve affordability and adherence. Sofosbuvir and ledipasvir with ribavirin have high efficacy when taken for 8 weeks but not for 6 weeks. We assessed whether the addition of a third direct-acting antiviral drug to sofosbuvir and ledipasvir would allow a shorter treatment duration. METHODS: In this single-centre, open-label, phase 2A trial, we sequentially enrolled treatment-naive patients with HCV genotype 1 infection into three treatment groups: 12 weeks of sofosbuvir and ledipasvir; 6 weeks of sofosbuvir, ledipasvir, and GS-9669; or 6 weeks of sofosbuvir, ledipasvir, and GS-9451. Patients and investigators were not masked to treatment assignment. The primary endpoint was the propotion of patients with sustained viral response at 12 weeks after treatment completion (SVR12), assessed by serum HCV RNA concentrations lower than 43 IU/mL (the lower limit of quantification). We did an intention-to-treat analysis for the primary endpoint and adverse events. This study is registered with ClinicalTrials.gov, number NCT01805882. FINDINGS: Between Jan 11, 2013, and Dec 17, 2013, we enrolled 60 patients, and sequentially assigned them into three groups of 20. We noted an SVR12 in all 20 patients (100%, 95% CI 83-100) allocated to sofosbuvir and ledipasvir for 12 weeks; in 19 (95%, 75-100) of the 20 patients allocated to sofosbuvir, ledipasvir, and GS-9669 for 6 weeks (one patient relapsed 2 weeks after completion of treatment); and in 19 (95%, 75-100%) of the 20 patients allocated to sofosbuvir, ledipasvir, and GS-9451 for 6 weeks (one patient was lost to follow-up after reaching sustained viral response at 4 weeks). Most adverse events were mild and no patients discontinued treatment. Two serious adverse events occurred (pain after a post-treatment liver biopsy and vertigo), both unrelated to study drugs. INTERPRETATION: In this small proof-of-concept study, two different three-drug regimens that were given for 6 weeks resulted in high cure rates for HCV infection with excellent tolerability. Addition of a third potent direct-acting antiviral drug can reduce the duration of treatment required to achieve sustained viral response in patients with chronic HCV genotype 1 infection without cirrhosis. FUNDING: National Institute of Allergy and Infectious Diseases (NIAID), National Cancer Institute and Clinical Center Intramural Program, German Research Foundation, National Institutes of Health, Gilead Sciences.


Subject(s)
Antiviral Agents/therapeutic use , Benzimidazoles/therapeutic use , Fluorenes/therapeutic use , Furans/therapeutic use , Hepatitis C, Chronic/drug therapy , Quinolines/therapeutic use , RNA, Viral/blood , Ribavirin/therapeutic use , Thiophenes/therapeutic use , Uridine Monophosphate/analogs & derivatives , Aged , Cohort Studies , Drug Therapy, Combination/methods , Female , Hepacivirus/genetics , Humans , Intention to Treat Analysis , Male , Middle Aged , Sofosbuvir , Treatment Outcome , Uridine Monophosphate/therapeutic use , Viral Load
8.
Ann Intern Med ; 161(9): 634-8, 2014 Nov 04.
Article in English | MEDLINE | ID: mdl-25364884

ABSTRACT

BACKGROUND: The interferon (IFN)-free regimen of sofosbuvir and ribavirin for 24 weeks was recently approved to treat chronic hepatitis C virus (HCV) genotype 1 (GT-1) infection for patients ineligible for IFN. However, sofosbuvir plus ribavirin therapy is associated with relapse in 15% to 30% of patients with HCV GT-1. Neither the mechanism of relapse nor the optimal re-treatment strategy for these patients is defined. OBJECTIVE: To assess the safety and efficacy of sofosbuvir plus ledipasvir in patients with chronic HCV GT-1 that relapsed after sofosbuvir plus ribavirin therapy. DESIGN: Phase 2a, open-label study. (ClinicalTrials.gov: NCT01805882). SETTING: Single U.S site. PATIENTS: 14 patients with HCV GT-1 that relapsed after treatment with sofosbuvir plus ribavirin for 24 weeks were re-treated with sofosbuvir plus ledipasvir for 12 weeks. MEASUREMENTS: HCV RNA concentration and population sequencing to detect NS5B S282T mutations. RESULTS: All 14 patients treated with sofosbuvir plus ledipasvir for 12 weeks achieved a sustained virologic response, including 7 with advanced liver disease (Knodell Histology Activity Index score of 3 or 4) and 1 with a detectable NS5B S282T mutation after sofosbuvir plus ribavirin therapy. Sofosbuvir plus ledipasvir was well-tolerated with few adverse events. Four grade 3 events (elevated serum creatinine in a patient with baseline renal insufficiency, hypercholesterolemia, and hypophosphatemia) occurred. There were no grade 4 events or treatment discontinuations. LIMITATION: Small sample size. CONCLUSION: The fixed-dose combination of sofosbuvir plus ledipasvir was efficacious in a small cohort of patients with HCV GT-1 that relapsed after sofosbuvir plus ribavirin therapy, even in the setting of advanced liver disease. Larger studies are needed to confirm these preliminary efficacy results. PRIMARY FUNDING SOURCE: National Institute of Allergy and Infectious Diseases, National Institutes of Health, National Cancer Institute, and Gilead Sciences.


Subject(s)
Antiviral Agents/therapeutic use , Benzimidazoles/therapeutic use , Fluorenes/therapeutic use , Hepacivirus/genetics , Hepatitis C, Chronic/drug therapy , Uridine Monophosphate/analogs & derivatives , Aged , Antiviral Agents/adverse effects , Benzimidazoles/adverse effects , Drug Therapy, Combination , Fluorenes/adverse effects , Genotype , Hepatitis C, Chronic/blood , Hepatitis C, Chronic/virology , Humans , Male , Middle Aged , Mutation , RNA, Viral/blood , Recurrence , Ribavirin/therapeutic use , Sofosbuvir , Uridine Monophosphate/adverse effects , Uridine Monophosphate/therapeutic use
9.
AIDS Res Hum Retroviruses ; 30(8): 792-5, 2014 Aug.
Article in English | MEDLINE | ID: mdl-24946792

ABSTRACT

Single nucleotide polymorphisms (SNPs) have become important in predicting treatment response to interferon containing anti-hepatitis C virus (HCV) therapy in HCV and HIV/HCV-infected patients. A reliable method for extracting host DNA from serum for genotyping assays would present a practical alternative for clinicians and investigators seeking to perform SNP analyses in HCV-infected patients, particularly in resource-limited settings. Human genomic DNA was extracted from peripheral blood mononuclear cells (PBMCs) and serum of 51 HIV/HCV coinfected patients using the QIAamp DNA Blood Mini Kit and QIAamp Min Elute Virus Spin Kit, respectively. Genotyping assays for the IL28B SNP (rs12979860) and SOCS3 SNP (rs4969170) were performed using the commercially available ABI Taqman allelic discrimination kit and reverse transcriptase-polymerase chain reaction (RT-PCR) was performed using 50 cycles. Results of the genotyping assays using DNA from both PBMCs and cell-free serum were determined separately and then analyzed for concurrence. Genotype analyses performed using DNA isolated from PBMCs or cell-free serum showed a 100% agreement between the IL28B genotyping results from the serum and PBMC isolates and 98% agreement for SOCS3 SNP. This novel serum-based assay to isolate DNA fragments from the serum of HIV/HCV-coinfected subjects can accurately determine a subject's genotype for IL28B (rs12979860) and SOCS3 (rs4969170). This assay could be immediately valuable for detecting clinically relevant SNPs from serum in cases in which PBMCs are not available.


Subject(s)
Genotyping Techniques/methods , HIV Infections/complications , Hepatitis C, Chronic/complications , Interleukins/genetics , Polymorphism, Single Nucleotide , Serum/chemistry , Suppressor of Cytokine Signaling Proteins/genetics , Adult , Aged , Female , HIV Infections/genetics , Hepatitis C, Chronic/genetics , Humans , Interferons , Male , Middle Aged , Suppressor of Cytokine Signaling 3 Protein
10.
AIDS Res Hum Retroviruses ; 30(8): 775-82, 2014 Aug.
Article in English | MEDLINE | ID: mdl-24856902

ABSTRACT

Patients coinfected with HIV and hepatitis C virus (HCV) have poor to modest rates of response with interferon-based therapies, which remain a backbone of the treatment in HIV/HCV-coinfected patients. The mechanisms responsible for poor responsiveness to interferon are not well described. In this study a targeted proteomic analysis of plasma from 42 patients infected with both HIV and HCV and undergoing therapy for HCV with peginterferon and ribavirin was performed. Higher baseline plasma levels of interleukin (IL)-23 were associated with sustained virologic response. Further investigation of how IL-23 facilitates interferon (IFN) responsiveness, as evidenced by a >2-fold increase in most interferon-stimulated genes (ISGs), revealed that IL-23 indirectly enhances IFN signaling in peripheral blood mononuclear cells and HCV continuous culture system by preventing the down-regulation of the IFNAR2 receptor after exposure to IFN-α. These findings suggest a unique role of the IL-23 pathway in enhancing host response to type I interferons, thereby facilitating eradication of HCV. Low levels of IL-23 present in plasma of nonresponders may reflect an impaired immune state that in the case of HIV/HCV-coinfected subjects could potentially lead to disruption of TH17 CD4(+) T cells. This study suggests a major role for HIV-associated immune dysregulation present in HIV-infected subjects that subsequently determines the overall responsiveness to exogenous interferon-α-based HCV therapy.


Subject(s)
Antiviral Agents/therapeutic use , HIV Infections/complications , Hepatitis C, Chronic/complications , Hepatitis C, Chronic/drug therapy , Interferon-alpha/therapeutic use , Interleukin-23/blood , Adult , Aged , Female , Gene Expression , Humans , Leukocytes, Mononuclear/immunology , Leukocytes, Mononuclear/virology , Male , Middle Aged , Receptor, Interferon alpha-beta/biosynthesis , Ribavirin/therapeutic use , Treatment Outcome , Viral Load
11.
Hepatol Int ; 8(4): 560-6, 2014 Oct.
Article in English | MEDLINE | ID: mdl-26202761

ABSTRACT

BACKGROUND: Triple therapy for the treatment of hepatitis C virus (HCV) with first-generation directly acting antiviral agents, the non-structural serine protease inhibitors boceprevir (BOC) and telaprevir have resulted in improved sustained virologic response (SVR) rates. However, a high incidence of adverse events (AEs), high pill burdens and drug interactions remain significant barriers to successful completion of therapy. The aim of this study was to evaluate the AEs observed with BOC triple therapy in comparison to IFN-free sofosbuvir/ribavirin (SOF/RBV) therapy in HCV monoinfected, genotype-1 (GT-1) individuals. METHODS: We retrospectively evaluated HCV monoinfected, treatment-naïve or -experienced, GT-1 individuals treated with either BOC/IFN/RBV at the Veterans Affairs Medical Center, Baltimore (n = 97) or SOF/RBV in the NIAID SPARE clinical trial (n = 60). AEs, namely hematologic (hemoglobin, neutrophil and platelet counts), hepatic (alanine transaminase or bilirubin) and renal (eGFR), were measured according to the DAIDS toxicity table (version 1.0). RESULTS: BOC/IFN/RBV was associated with significantly more AEs, most commonly neutropenia, anemia and thrombocytopenia. In the SOF/RBV cohort, five (8 %) patients discontinued treatment early, but none (0 %) were because of AEs, while 60 (62 %) patients on triple therapy discontinued treatment early, 34 (57 %) because of AEs. SVR24 rates were 68 versus 34 % with SOF/RBV versus BOC/IFN/RBV. CONCLUSIONS: SOF/RBV treatment was associated with fewer side effects than BOC-based triple therapy, appearing to be a safer and more tolerable alternative for HCV GT-1 subjects. These results show that emerging IFN-free therapies may enhance patient adherence, allowing treatment of larger number of patients with improved efficacy.

12.
Biotechnol Prog ; 21(3): 959-64, 2005.
Article in English | MEDLINE | ID: mdl-15932280

ABSTRACT

This study investigated and correlated physical properties and cell interactions of copolymers obtained by a poly(ethylene glycol) (PEG)-modulated fermentation of Azotobacter vinelandii UWD. PEGs with molecular weights of 400 and 3400 Da and di(ethylene glycol) (DEG) were used to modulate the bacterial synthesis of poly(beta-hydroxybutyrate) (PHB). The PHB crystallinity was determined by wide-angle X-ray scattering (WAXS). Small-angle X-ray scattering (SAXS) showed that lamellar distances decreased between the PHB and the PHB modulated with PEG or DEG. Furthermore, the contact angle of water on the PHB/PEG polymer surfaces decreased when compared to that of PHB. The significant decrease of the contact angle and corresponding increase in surface tension, as well as significant decrease in cell adhesion, suggest the presence of hydrophilic PEG and DEG within the hydrophobic surface.


Subject(s)
Azotobacter vinelandii/cytology , Azotobacter vinelandii/metabolism , Ethylene Glycols/chemistry , Hydroxybutyrates/chemistry , Polyesters/chemistry , Polyethylene Glycols/chemistry , Cell Adhesion/physiology , Ethylene Glycols/analysis , Hydroxybutyrates/analysis , Macromolecular Substances/analysis , Macromolecular Substances/chemistry , Materials Testing , Molecular Conformation , Polyesters/analysis , Polyethylene Glycols/analysis , Polymers/analysis , Polymers/chemistry , Surface Properties , X-Ray Diffraction/methods
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