http://www.mdpi.com/journal/ijms/special_issues/biodegradability-of-materials/ To protect environment, the biodegradable materials have great advantages. However, sometimes, for material stability, biodegradation is a problem, for example, the biomedical materials. Related Special Issues in other Journals Biodegradability of Materials in Materials Biodegradability and Environmental Sciences in the Int. J. Environ. Res. Pub. Health Biodegradation: Organic, Medicinal and Analytical Chemistry in Molecules Submission All papers should be submitted to ijms@mdpi.com. To be published continuously until the deadline and papers will be listed together at the special issue website. Submitted papers should not have been published previously, nor be under consideration for publication elsewhere. All papers are refereed through a peer-review process. A guide for authors is available on the Instructions for Authors page. The International Journal of Molecular Sciences is an international peer-reviewed monthly journal published by MDPI. Open Access publication fees are 800 CHF per paper. English correction fees and/or formatting fees (250 CHF) will be added in certain cases (1050 CHF per paper for those papers that require extensive additional formatting and/or English corrections). http://www.mdpi.com/1422-0067/10/10/4267/ The biodegradabilities of poly(butylene succinate) (PBS) powders in a controlled compost at 58 °C have been studied using a Microbial Oxidative Degradation Analyzer (MODA) based on the ISO 14855-2 method, entitled “Determination of the ultimate aerobic biodegradability of plastic materials under controlled composting conditions—Method by analysis of evolved carbon dioxide—Part 2: Gravimetric measurement of carbon dioxide evolved in a laboratory-scale test”. The evolved CO2 was trapped by an additional aqueous Ba(OH)2 solution. The trapped BaCO3 was transformed into graphite via a serial vaporization and reduction reaction using a gas-tight tube and vacuum manifold system. This graphite was analyzed by accelerated mass spectrometry (AMS) to determine the percent modern carbon [pMC (sample)] based on the 14C radiocarbon concentration. By using the theory that pMC (sample) was the sum of the pMC (compost) (109.87%) and pMC (PBS) (0%) as the respective ratio in the determined period, the CO2 (respiration) was calculated from only one reaction vessel. It was found that the biodegradabilities determined by the CO2 amount from PBS in the sample vessel were about 30% lower than those based on the ISO method. These differences between the ISO and AMS methods are caused by the fact that part of the carbons from PBS are changed into metabolites by the microorganisms in the compost, and not changed into CO2. http://www.mdpi.com/1422-0067/10/10/4267/ Wed, 30 Sep 2009 00:00:00 CEST International Journal of Molecular Sciences 2009-09-30 10 10 Article 4267 4283 1422-0067 Biodegradation of Poly(butylene succinate) Powder in a Controlled Compost at 58 °C Evaluated by Naturally-Occurring Carbon 14 Amounts in Evolved CO2 Based on the ISO 14855-2 Method 2009-09-30 doi: 10.3390/ijms10104267 Masao Kunioka Fumi Ninomiya Masahiro Funabashi http://www.mdpi.com/1422-0067/10/10/4223/ This article reviews the degradability of chemically synthesized bioelastomers, mainly designed for soft tissue repair. These bioelastomers involve biodegradable polyurethanes, polyphosphazenes, linear and crosslinked poly(ether/ester)s, poly(ε-caprolactone) copolymers, poly(1,3-trimethylene carbonate) and their copolymers, poly(polyol sebacate)s, poly(diol-citrates) and poly(ester amide)s. The in vitro and in vivo degradation mechanisms and impact factors influencing degradation behaviors are discussed. In addition, the molecular designs, synthesis methods, structure properties, mechanical properties, biocompatibility and potential applications of these bioelastomers were also presented. http://www.mdpi.com/1422-0067/10/10/4223/ Tue, 29 Sep 2009 00:00:00 CEST International Journal of Molecular Sciences 2009-09-29 10 10 Review 4223 4256 1422-0067 Recent Advances in Synthetic Bioelastomers 2009-09-29 doi: 10.3390/ijms10104223 Rui Shi Dafu Chen Quanyong Liu Yan Wu Xiaochuan Xu Liqun Zhang Wei Tian http://www.mdpi.com/1422-0067/10/9/4033/ Many key components of implantable medical devices are made from polymeric materials. The functions of these materials include structural support, electrical insulation, protection of other materials from the environment of the body, and biocompatibility, as well as other things such as delivery of a therapeutic drug. In such roles, the stability and integrity of the polymer, over what can be a very long period of time, is very important. For most of these functions, stability over time is desired, but in other cases, the opposite–the degradation and disappearance of the polymer over time is required. In either case, it is important to understand both the chemistry that can lead to the degradation of polymers as well as the kinetics that controls these reactions. Hydrolysis and oxidation are the two classes of reactions that lead to the breaking down of polymers. Both are discussed in detail in the context of the environmental factors that impact the utility of various polymers for medical device applications. Understanding the chemistry and kinetics allows prediction of stability as well as explanations for observations such as porosity and the unexpected behavior of polymeric composite materials in some situations. In the last part, physical degradation such interfacial delamination in composites is discussed. http://www.mdpi.com/1422-0067/10/9/4033/ Fri, 11 Sep 2009 00:00:00 CEST International Journal of Molecular Sciences 2009-09-11 10 9 Review 4033 4065 1422-0067 Degradability of Polymers for Implantable Biomedical Devices 2009-09-11 doi: 10.3390/ijms10094033 SuPing Lyu Darrel Untereker http://www.mdpi.com/1422-0067/10/9/3824/ Anaerobic biodegradation tests of poly(lactic acid) (PLA) powder were done at the thermophilic (55 °C) and mesophilic temperature (35 °C) under aquatic conditions [total solid concentrations of the used sludge were 2.07% (at 55 °C) and 2.24% (at 35 °C)] using a newly developed evaluation system. With this system, the evolved biogas is collected in a gas sampling bag at atmospheric pressure. This method is more convenient than using a pressure transducer or inverted graduated cylinder submerged in water. PLA was degraded about 60% in 30 days, about 80% in 40 days and about 90% in 60 days at 55 °C. On the other hand, the PLA degradation started in 55 days at 35 °C and degradation rate was much slower than at 55 °C. http://www.mdpi.com/1422-0067/10/9/3824/ Wed, 02 Sep 2009 00:00:00 CEST International Journal of Molecular Sciences 2009-09-02 10 9 Article 3824 3835 1422-0067 Anaerobic Biodegradation Tests of Poly(lactic acid) under Mesophilic and Thermophilic Conditions Using a New Evaluation System for Methane Fermentation in Anaerobic Sludge 2009-09-02 doi: 10.3390/ijms10093824 Hisaaki Yagi Fumi Ninomiya Masahiro Funabashi Masao Kunioka http://www.mdpi.com/1422-0067/10/9/3722/ Plastic is a broad name given to different polymers with high molecular weight, which can be degraded by various processes. However, considering their abundance in the environment and their specificity in attacking plastics, biodegradation of plastics by microorganisms and enzymes seems to be the most effective process. When plastics are used as substrates for microorganisms, evaluation of their biodegradability should not only be based on their chemical structure, but also on their physical properties (melting point, glass transition temperature, crystallinity, storage modulus etc.). In this review, microbial and enzymatic biodegradation of plastics and some factors that affect their biodegradability are discussed. http://www.mdpi.com/1422-0067/10/9/3722/ Wed, 26 Aug 2009 00:00:00 CEST International Journal of Molecular Sciences 2009-08-26 10 9 Review 3722 3742 1422-0067 Biodegradability of Plastics 2009-08-26 doi: 10.3390/ijms10093722 Yutaka Tokiwa Buenaventurada P. Calabia Charles U. Ugwu Seiichi Aiba http://www.mdpi.com/1422-0067/10/8/3635/ Biodegradabilities of polymers and their composites in a controlled compost were described. Polycaprolactone (PCL) and poly(lactic acid) (PLA) were employed as biodegradable polymers. Biodegradabilities of PCL and PLA samples in a controlled compost were measured using a Microbial Oxidative Degradation Analyzer (MODA) according to ISO 14855-2. Sample preparation method for biodegradation test according to ISO/DIS 10210 was also described. Effects of sizes and shapes of samples on biodegradability were studied. Reproducibility of biodegradation test of ISO 14855-2 by MODA was confirmed. Validity of sample preparation method for polymer pellets, polymer film, and polymer products of ISO/DIS 10210 for ISO 14855-2 was confirmed. http://www.mdpi.com/1422-0067/10/8/3635/ Tue, 18 Aug 2009 00:00:00 CEST International Journal of Molecular Sciences 2009-08-18 10 8 Review 3635 3654 1422-0067 Biodegradability Evaluation of Polymers by ISO 14855-2 2009-08-18 doi: 10.3390/ijms10083635 Masahiro Funabashi Fumi Ninomiya Masao Kunioka http://www.mdpi.com/1422-0067/10/8/3599/ We have developed a mulch sheet made by inflation molding of PLA, Ecoflex® and modified starch, which all have different biodegradabilities. A field test of use as an agricultural mulch sheet for mandarin oranges was carried out over two years. The mechanical properties of the mulch sheet were weakened with time during the field test, but the quality of the mandarin oranges increased, a result of the controlled degradation of the sheet. The most degradable modified starch degraded first, allowing control of the moisture on the soil. Accelerator mass spectroscopy was used for evaluation of the biomass carbon ratio. The biomass carbon ratio decreased by degradation of the biobased materials, PLA and modified starch in the mulch sheet. http://www.mdpi.com/1422-0067/10/8/3599/ Mon, 17 Aug 2009 00:00:00 CEST International Journal of Molecular Sciences 2009-08-17 10 8 Article 3599 3615 1422-0067 Utilization of a Biodegradable Mulch Sheet Produced from Poly(Lactic Acid)/Ecoflex®/Modified Starch in Mandarin Orange Groves 2009-08-17 doi: 10.3390/ijms10083599 Yuya Tachibana Takuya Maeda Osamu Ito Yasukatsu Maeda Masao Kunioka http://www.mdpi.com/1422-0067/10/5/1942/ Fluoroaromatic compounds are used as agrochemicals and released into environment as pollutants. Glycosylation of 2-, 3-, and 4-fluorophenols using plant cell cultures of Nicotiana tabacum was investigated to elucidate their potential to metabolize these compounds. Cultured N. tabacum cells converted 2-fluorophenol into its β-glucoside (60%) and β-gentiobioside (10%). 4-Fluorophenol was also glycosylated to its β-glucoside (32%) and β-gentiobioside (6%) by N. tabacum cells. On the other hand, N. tabacum glycosylated 3-fluorophenol to β-glucoside (17%). http://www.mdpi.com/1422-0067/10/5/1942/ Mon, 27 Apr 2009 00:00:00 CEST International Journal of Molecular Sciences 2009-04-27 10 5 Article 1942 1949 1422-0067 Glycosylation of Fluorophenols by Plant Cell Cultures 2009-04-27 doi: 10.3390/ijms10051942 Kei Shimoda Naoji Kubota Yoko Kondo Daisuke Sato Hiroki Hamada http://www.mdpi.com/1422-0067/10/4/1514/ Silk fibroin from the silkworm, Bombyx mori, has excellent properties such as biocompatibility, biodegradation, non-toxicity, adsorption properties, etc. As a kind of ideal biomaterial, silk fibroin has been widely used since it was first utilized for sutures a long time ago. The degradation behavior of silk biomaterials is obviously important for medical applications. This article will focus on silk-based biomaterials and review the degradation behaviors of silk materials. http://www.mdpi.com/1422-0067/10/4/1514/ Tue, 31 Mar 2009 00:00:00 CEST International Journal of Molecular Sciences 2009-03-31 10 4 Review 1514 1524 1422-0067 Biodegradation of Silk Biomaterials 2009-03-31 doi: 10.3390/ijms10041514 Yang Cao Bochu Wang http://www.mdpi.com/1422-0067/10/2/589/ This paper reviews the synthesis, characterization, biodegradation and usage of bioresorbable polymers based on polydepsipeptides. The ring-opening polymerization of morpholine-2,5-dione derivatives using organic Sn and enzyme lipase is discussed. The dependence of the macroscopic properties of the block copolymers on their structure is also presented. Bioresorbable polymers based on polydepsipeptides could be used as biomaterials in drug controlled release, tissue engineering scaffolding and shape-memory materials. http://www.mdpi.com/1422-0067/10/2/589/ Fri, 13 Feb 2009 00:00:00 CET International Journal of Molecular Sciences 2009-02-13 10 2 Review 589 615 1422-0067 Biodegradable Polydepsipeptides 2009-02-13 doi: 10.3390/ijms10020589 Yakai Feng Jintang Guo