Physical performance of biodegradable films intended for antimicrobial food packaging

Antimicrobial films were prepared by including enterocins to alginate, polyvinyl alcohol (PVOH), and zein films. The physical performance of the films was assessed by measuring color, microstructure (SEM), water vapor permeability (WVP), and tensile properties. All studied biopolymers showed poor WVP and limited tensile properties. PVOH showed the best performance exhibiting the lowest WVP values, higher tensile properties, and flexibility among studied biopolymers. SEM of antimicrobial films showed increased presence of voids and pores as a consequence of enterocin addition. However, changes in microstructure did not disturb WVP of films. Moreover, enterocin-containing films showed slight improvement compared to control films. Addition of enterocins to PVOH films had a plasticizing effect, by reducing its tensile strength and increasing the strain at break. The presence of enterocins had an important effect on tensile properties of zein films by significantly reducing its brittleness. Addition of enterocins, thus, proved not to disturb the physical performance of studied biopolymers. Development of new antimicrobial biodegradable packaging materials may contribute to improving food safety while reducing environmental impact derived from packaging waste.

Childhood and malaria vaccines combined in biodegradable microspheres produce immunity with synergistic interactions.

Biodegradable microspheres may represent a potential tool for the delivery of combination vaccines. We demonstrate strong immunogenicity of five co-encapsulated antigens after a single subcutaneous inoculation in guinea pigs. Tetanus- and diphtheria-specific antibodies were not significantly affected by the presence of either antigen or by the presence of pertussis or Haemophilus influenzae type b (Hib) antigens. Microsphere formulations gave better protection against diphtheria toxin than did two injections of a licensed tetravalent vaccine. Finally, a synthetic malaria peptide antigen (PfCS) also encapsulated in PLGA microspheres increased diphtheria and tetanus-specific immunity and improved protection against diphtheria. These findings demonstrate the potential of microspheres as an alternative and promising strategy for combination vaccines with a further aptitude in reducing the number of inoculations required to gain functional immunity.

Randomized comparison of biodegradable polymer sirolimus-eluting stents versus durable polymer everolimus-eluting stents for percutaneous coronary revascularization: Rationale and design of the BIOSCIENCE trial.

BACKGROUND: Biodegradable polymers for release of antiproliferative drugs from metallic drug-eluting stents aim to improve long-term vascular healing and efficacy. We designed a large scale clinical trial to compare a novel thin strut, cobalt-chromium drug-eluting stent with silicon carbide-coating releasing sirolimus from a biodegradable polymer (O-SES, Orsiro; Biotronik, Bülach, Switzerland) with the durable polymer-based Xience Prime/Xpedition everolimus-eluting stent (EES) (Xience Prime/Xpedition stent, Abbott Vascular, IL) in an all-comers patient population. DESIGN: The multicenter BIOSCIENCE trial (NCT01443104) randomly assigned 2,119 patients to treatment with biodegradable polymer sirolimus-eluting stents (SES) or durable polymer EES at 9 sites in Switzerland. Patients with chronic stable coronary artery disease or acute coronary syndromes, including non-ST-elevation and ST-elevation myocardial infarction, were eligible for the trial if they had at least 1 lesion with a diameter stenosis >50% appropriate for coronary stent implantation. The primary end point target lesion failure (TLF) is a composite of cardiac death, target vessel myocardial infarction, and clinically driven target lesion revascularization within 12 months. Assuming a TLF rate of 8% at 12 months in both treatment arms and accepting 3.5% as a margin for noninferiority, inclusion of 2,060 patients would provide more than 80% power to detect noninferiority of the biodegradable polymer SES compared with the durable polymer EES at a 1-sided type I error of 0.05. Clinical follow-up will be continued through 5 years. CONCLUSION: The BIOSCIENCE trial will determine whether the biodegradable polymer SES is noninferior to the durable polymer EES with respect to TLF.

Effects of inorganic nitrogen (NH4Cl) and biodegradable organic carbon (CH3COONa) additions on a pilot-scale seawater biofilter

Biofilters degrade only a small fraction of the natural organic matter (NOM) contained in seawater which is the leading cause of biofouling in downstream processes. This work studies the effects of chemical additions on NOM biodegradation by biofilters. In this work, biofiltration of seawater with an empty bed contact time (EBCT) of 6 min and a hydraulic loading rate of 10 m h-1 reduces the biological oxygen demand (BOD7) by 8%, the dissolved organic carbon (DOC) by 6% and the UV absorbance at 254 nm (A254) by 7%. Different amounts of ammonium chloride are added to the seawater (up to twice the total dissolved nitrogen in untreated seawater) to study its possible effect on the removal of NOM by a pilot-scale biofilter. Seawater is amended with different amounts of easily biodegradable dissolved organic carbon (BDOC) supplied as sodium acetate (up to twice the DOC) for the same purpose. The results of this work reveal that the ammonium chloride additions do not significantly affect NOM removal and the sodium acetate is completely consumed by the biofiltration process. For both types of chemical additions, the BOD7, DOC and A254 in the outlet stream of the biofilter are similar to the values for the untreated control. These results indicate that this biofilter easily removes the BDOC from the seawater when the EBCT is not above 6 min. Furthermore, nitrogen does not limit the NOM biodegradation in seawater under these experimental conditions.

Organisational Buying Decision Process for Biodegradable Implants

Työn tavoitteena oli selvittää organisaation ostopäätösprosessi, kun tuotteina ovat biohajoavat kasvo- ja kallokirurgian implantit. Ensin selvitettiin biohajoavien implanttien markkinapotentiaalia, biohajoavien materiaalien lisäksi implanttien valmistuksessa käytettäviä muita materiaaleja sekä implanteilta vaadittavia ominaisuuksia kirjallisuuden ja internetin sekä asiantuntijahaastatteluiden avulla. Kirjallisuuden avulla selvitettiin myös organisaatioiden ostopäätösprosessien yleisiä piirteitä ja vaiheita. Biohajoavien kasvo- ja kallokirurgian implanttien ostopäätösprosessia tutkittiin kirjallisen kyselytutkimuksen avulla, joka oli suunnattu alan asiantuntijoille Euroopassa, Yhdysvalloissa sekä Kanadassa. Tutkimuksessa selvitettiin mm. tärkeimpiä käytettävien implanttien materiaalivalintaan vaikuttavia kriteereitä, ostopäätösprosessiin osallistuvia organisaation jäseniä, sekä heidän roolejaan päätöksenteossa, implantteja koskevan informaation etsintää sekä ostopäätösprosessin vaiheita. Kirjallisuudesta, internetistä, asiantuntijahaastatteluista ja kyselytutkimuksesta saatu tieto koottiin vuokaaviomalliksi, joka kuvaa kasvo- ja kallokirurgian implanttien ostopäätösprosessia organisaatioissa. Lopuksi esitettiin myös ehdotuksia markkinointisuunnitelmaan sekä jatkotutkimusehdotukset.

Peripheral Nerve Repair: Multimodal Comparison of the Long-Term Regenerative Potential of Adipose Tissue-Derived Cells in a Biodegradable Conduit.

Tissue engineering is a popular topic in peripheral nerve repair. Combining a nerve conduit with supporting adipose-derived cells could offer an opportunity to prevent time-consuming Schwann cell culture or the use of an autograft with its donor site morbidity and eventually improve clinical outcome. The aim of this study was to provide a broad overview over promising transplantable cells under equal experimental conditions over a long-term period. A 10-mm gap in the sciatic nerve of female Sprague-Dawley rats (7 groups of 7 animals, 8 weeks old) was bridged through a biodegradable fibrin conduit filled with rat adipose-derived stem cells (rASCs), differentiated rASCs (drASCs), human (h)ASCs from the superficial and deep abdominal layer, human stromal vascular fraction (SVF), or rat Schwann cells, respectively. As a control, we resutured a nerve segment as an autograft. Long-term evaluation was carried out after 12 weeks comprising walking track, morphometric, and MRI analyses. The sciatic functional index was calculated. Cross sections of the nerve, proximal, distal, and in between the two sutures, were analyzed for re-/myelination and axon count. Gastrocnemius muscle weights were compared. MRI proved biodegradation of the conduit. Differentiated rat ASCs performed significantly better than undifferentiated rASCs with less muscle atrophy and superior functional results. Superficial hASCs supported regeneration better than deep hASCs, in line with published in vitro data. The best regeneration potential was achieved by the drASC group when compared with other adipose tissue-derived cells. Considering the ease of procedure from harvesting to transplanting, we conclude that comparison of promising cells for nerve regeneration revealed that particularly differentiated ASCs could be a clinically translatable route toward new methods to enhance peripheral nerve repair.

Study on the removal of biodegradable NOM from seawater using biofiltration

Despite the low biodegradability of seawater NOM, problems associated with biofouling are common in facilities that handle seawater. In this work, a fixed-film aerobic biofilter is proposed as an effective unit for preventing biofouling in such facilities. A packed-bed biofilter with an EBCT = 6 - 11 min was employed. The results demonstrated that the DOC is reduced by 6% and the BOD7 is reduced up to 15%. The LC-OCD analysis revealed that biofiltration abates the LMW neutrals and biopolymer fractions by 33 and 17%, respectively. However, the fractionation with UF membrane showed that the biofiltration process is able to degrade the more biodegradable compounds that have molecular weights that are greater than 1 kDa and compounds with molecular weights of less than 1 kDa. After biofiltration, the biological activity measured in terms of ATP removal was reduced by 60%. Finally, a test to evaluate the biofilm formation capacity of a water sample revealed reductions of ~94% when comparing biofiltered and non-biofiltered seawater. Therefore, a fixed-film aerobic biofiltration process could be a useful treatment for the removal of biodegradable organic matter from seawater and for improving the water quality in terms of less biofilm formation capacity.

High-Performance-Tensile-Strength Alpha-Grass Reinforced Starch-Based Fully Biodegradable Composites

Though there has been a great deal of work concerning the development of natural fibers in reinforced starch-based composites, there is still more to be done. In general, cellulose fibers have lower strength than glass fibers; however, their specific strength is not far from that of fiberglass. In this work, alpha-fibers were obtained from alpha-grass through a mild cooking process. The fibers were used to reinforce a starch-based biopolymer. Composites including 5 to 35% (w/w) alpha-grass fibers in their formulation were prepared, tested, and subsequently compared with those of wood- and fiberglass-reinforced polypropylene (PP). The term “high-performance” refers to the tensile strength of the studied composites and is mainly due to a good interphase, a good dispersion of the fibers inside the matrix, and a good aspect ratio. The tensile strength of the composites showed a linear evolution for fiber contents up to 35% (w/w). The strain at break of the composites decreased with the fiber content and showed the stiffening effects of the reinforcement. The prepared composites showed high mechanical properties, even approaching those of glass fiber reinforced composites

Development and validation of a high performance liquid chromatographic method for determination of cyclosporine-A from biodegradable intraocular implants

An HPLC method was developed and validated aiming to quantify the cyclosporine-A incorporated into intraocular implants, released from them; and in direct contact with the degradation products of PLGA. The separation was carried out in isocratic mode using acetonitrile/water (70:30) as mobile phase, a C18 column at 80 ºC and UV detection at 210 nm. The method provided selectivity based on resolution among peaks. It was linear over the range of 2.5-40.0 µg/mL. The quantitation and detection limits were 0.8 and 1.2 µg/mL, respectively. The recovery was 101.8% and intra-day and inter-day precision was close to 2%.

Development and validation of a High Performance Liquid Chromatographic method for determination of etoposide in biodegradable polymeric implants

A method using HPLC-UV was developed and validated for the determination of etoposide incorporated into polycaprolactone implants. The method was carried out in isocratic mode using a C18 column (250 x 4.6 mm; 5 µm), at 25 ºC, with acetonitrile and acetic acid 4% (70:30) as mobile phase, a flow rate of 2 mL/min, and UV detection at 285 nm. The method was linear (r² > 0.99) over the range of 5 to 65 µg/mL, precise (RSD < 5%), accurate (recovery of 98.7%), robust, selective regarding excipient of the sample, and had a quantitation limit equal to 1.76 µg/mL. The validated method can be successfully employed for routine quality control analyses.

Biodegradable nanoparticles obtained from zein as a drug delivery system for terpinen-4-ol

Biodegradable nanoparticles (NPs) have received considerable attention because of their possible use in the development of strategies for the topical delivery of oils and therapeutic drugs, particularly when drug penetration in dermis is desired. Zein is a prolamine and is a promising material for the design of drug delivery systems. In this study, NPs were prepared with zein and were used to encapsulate and release terpinen-4-ol, which is a therapeutic agent for the treatment of melanoma. The results show that the zein NPs are promising nanostructured systems for the prolonged delivery of T4OL with potential applications in anti-melanoma therapy.

Development and validation of a RP-HPLC method to determine the xanthyletin content in biodegradable polymeric nanoparticles

Xanthyletin is used as an inhibitor of the symbiotic fungus (Leucoagaricus gongylophorus) of the leaf-cutting ant (Atta sexdens rubropilosa), one of the most significant agricultural plague insects. The incorporation of this compound into nanoparticles is a promising approach to effectively control leaf-cutting ants. This study presents the development and validation of a specific analytical method using high-performance liquid chromatography (HPLC) for quantification of the xanthyletin content in biodegradable polymeric nanoparticles. The analytical methodology developed was specific, linear, accurate, precise, and robust. The absolute recovery of xanthyletin in colloidal suspensions was nearly 100%. The HPLC method proved reliable for the quantification of xanthyletin content in nanoparticle formulations.

Biodegradable packaging materials in 2013 and their feasibility in chocolate industry

The development of biopolymers has been rapid in recent years and the range of available bioplastics is increasing continuously, driven by a growing demand for sustainable solutions. There are several key drivers behind this growth. The oil reservoirs are decreasing which is causing a price increase for the traditional plastic materials and therefore the gap to bioplastics’ price is getting smaller. In addition, other environmental topics, such as waste disposal and green production, have become more and more important factors for institutes, companies and consumers. Legislation and directives have to be taken into account as well in decision making concerning different packaging materials. The new environmental law with waste disposal responsibility will also have an effect on the packaging business. Therefore a need has risen to study closer the current offering closer of bio-based materials that could be used in chocolate packaging. In this Master’s Thesis the bioplastics’, and especially biodegradable materials’ technical properties and their development, availability, possible existing products in the markets, waste disposal possibilities and consumers attitude towards environmental friendly packaging is studied. This is a case study where the offering of biodegradable materials was investigated during March 2013 for Fazer Confectionary.

Biogas production in regional integrated biodegradable waste treatment – Possibilities for improving energy performance and reducing GHG emissions

The greatest threat that the biodegradable waste causes on the environment is the methane produced in landfills by the decomposition of this waste. The Landfill Directive (1999/31/EC) aims to reduce the landfilling of biodegradable waste. In Finland, 31% of biodegradable municipal waste ended up into landfills in 2012. The pressure of reducing disposing into landfills is greatly increased by the forthcoming landfill ban on biodegradable waste in Finland. There is a need to discuss the need for increasing the utilization of biodegradable waste in regional renewable energy production to utilize the waste in a way that allows the best possibilities to reduce GHG emissions. The objectives of the thesis are: (1) to find important factors affecting renewable energy recovery possibilities from biodegradable waste, (2) to determine the main factors affecting the GHG balance of biogas production system and how to improve it and (3) to find ways to define energy performance of biogas production systems and what affects it. According to the thesis, the most important factors affecting the regional renewable energy possibilities from biodegradable waste are: the amount of available feedstock, properties of feedstock, selected utilization technologies, demand of energy and material products and the economic situation of utilizing the feedstocks. The biogas production by anaerobic digestion was seen as the main technology for utilizing biodegradable waste in agriculturally dense areas. The main reason for this is that manure was seen as the main feedstock, and it can be best utilized with anaerobic digestion, which can produce renewable energy while maintaining the spreading of nutrients on arable land. Biogas plants should be located close to the heat demand that would be enough to receive the produced heat also in the summer months and located close to the agricultural area where the digestate could be utilized. Another option for biogas use is to upgrade it to biomethane, which would require a location close to the natural gas grid. The most attractive masses for biogas production are municipal and industrial biodegradable waste because of gate fees the plant receives from them can provide over 80% of the income. On the other hand, directing gate fee masses for small-scale biogas plants could make dispersed biogas production more economical. In addition, the combustion of dry agricultural waste such as straw would provide a greater energy amount than utilizing them by anaerobic digestion. The complete energy performance assessment of biogas production system requires the use of more than one system boundary. These can then be used in calculating output–input ratios of biogas production, biogas plant, biogas utilization and biogas production system, which can be used to analyze different parts of the biogas production chain. At the moment, it is difficult to compare different biogas plants since there is a wide variation of definitions for energy performance of biogas production. A more consistent way of analyzing energy performance would allow comparing biogas plants with each other and other recovery systems and finding possible locations for further improvement. Both from the GHG emission balance and energy performance point of view, the energy consumption at the biogas plant was the most significant factor. Renewable energy use to fulfil the parasitic energy demand at the plant would be the most efficient way to reduce the GHG emissions at the plant. The GHG emission reductions could be increased by upgrading biogas to biomethane and displacing natural gas or petrol use in cars when compared to biogas CHP production. The emission reductions from displacing mineral fertilizers with digestate were seen less significant, and the greater N2O emissions from spreading digestate might surpass the emission reductions from displacing mineral fertilizers.

Comparison of the efficacy of biodegradable and non-biodegradable scintillation liquids on the counting of tritium- and [14C]-labeled compounds

The widespread use of ³H and 14C in research has generated a large volume of waste mixed with scintillation liquid, requiring an effective control and appropriate storage of liquid radioactive waste. In the present study, we compared the efficacy of three commercially available scintillation liquids, Optiphase HiSafe 3, Ultima-Gold™ AB (biodegradable) and Insta-Gel-XF (non-biodegradable), in terms of [14C]-glucose and [³H]-thymidine counting efficiency. We also analyzed the effect of the relative amount of water (1.6 to 50%), radioisotope concentration (0.1 to 100 nCi/ml), pH (2 to 10) and color of the solutions (samples containing 0.1 to 1.0 mg/ml of Trypan blue) on the counting efficiency in the presence of these scintillation liquids. There were few significant differences in the efficiency of 14C and ³H counting obtained with biodegradable or non-biodegradable scintillation liquids. However, there was an 83 and 94% reduction in the efficiency of 14C and ³H counting, respectively, in samples colored with 1 mg/ml Trypan blue, but not with 0.1 mg/ml, independent of the scintillation liquid used. Considering the low cost of biodegradable scintillation cocktails and their efficacy, these results show that traditional hazardous scintillation fluids may be replaced with the new safe biodegradable fluids without impairment of ³H and 14C counting efficiency. The use of biodegradable scintillation cocktails minimizes both human and environmental exposure to hazardous solvents. In addition, some biodegradable scintillation liquids can be 40% less expensive than the traditional hazardous cocktails.