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Special Issue "Biomedical Applications of Polylactide (PLA) and its Copolymers"

A special issue of Molecules (ISSN 1420-3049). This special issue belongs to the section "Medicinal Chemistry".

Deadline for manuscript submissions: closed (30 September 2017)

Special Issue Editors

Guest Editor
Prof. Dr. Gaetano Giammona

Laboratory of Biocompatible Polymers, Department of “Scienze e Tecnologie Biologiche, Chimiche e Farmaceutiche” (STEBICEF), University of Palermo, Via Archirafi, 32 90123 Palermo, Italy
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Interests: synthesis and physicochemical characterization of biocompatible polymers; innovative drug delivery systems; drug and gene delivery; hydrogels; three-dimensional scaffolds; tissue engineering; regenerative medicine; targeted release; lipid-based drug delivery systems; theranostic systems
Guest Editor
Dr. Emanuela Fabiola Craparo

Laboratory of Biocompatible Polymers, Department of “Scienze e Tecnologie Biologiche, Chimiche e Farmaceutiche” (STEBICEF), University of Palermo, Via Archirafi, 32 90123 Palermo, Italy
Website | E-Mail
Interests: functionalization and purification of biopolymers; controlled drug release; active targeting; micro- and nanoparticles; polymeric micelles; lipid-based nanostructured systems; polycations; gene therapy; imaging

Special Issue Information

Dear Colleagues,

The special Issue “Biomedical Applications of Polylactide (PLA) and its Copolymers” will be focused on current experimental research on the use of PLA, blended or functionalized with other biopolymers, for potential biomedical applications such as in the production of cell or drug delivery systems, applicable in controlled and/or targeted drug release, and in the fabrication of bioresorbable scaffolds for tissue engineering in regenerative medicine. Currently, PLA is already approved by the Food and Drug Administration (FDA) as a component in a wide range of biomedical and pharmaceutical products. This favorable approval arises from its excellent properties, such as biocompatibility, biodegradability and tunable mechanical and physicochemical properties, whereby it can be appropriately processed and engineered to allow a desired biomedical application.

Prof. Dr. Gaetano Giammona
Dr. Emanuela Fabiola Craparo
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All papers will be peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Molecules is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 1800 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • PLA-based copolymers
  • PLA blends
  • Innovative drug delivery systems
  • Cell delivery
  • Scaffolds
  • Targeted delivery
  • Regenerative medicine
  • Tissue engineering

Published Papers (7 papers)

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Research

Open AccessArticle Margination of Fluorescent Polylactic Acid–Polyaspartamide based Nanoparticles in Microcapillaries In Vitro: the Effect of Hematocrit and Pressure
Molecules 2017, 22(11), 1845; doi:10.3390/molecules22111845
Received: 11 October 2017 / Revised: 27 October 2017 / Accepted: 27 October 2017 / Published: 28 October 2017
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Abstract
The last decade has seen the emergence of vascular-targeted drug delivery systems as a promising approach for the treatment of many diseases, such as cardiovascular diseases and cancer. In this field, one of the major challenges is carrier margination propensity (i.e., particle migration
[...] Read more.
The last decade has seen the emergence of vascular-targeted drug delivery systems as a promising approach for the treatment of many diseases, such as cardiovascular diseases and cancer. In this field, one of the major challenges is carrier margination propensity (i.e., particle migration from blood flow to vessel walls); indeed, binding of these particles to targeted cells and tissues is only possible if there is direct carrier–wall interaction. Here, a microfluidic system mimicking the hydrodynamic conditions of human microcirculation in vitro is used to investigate the effect of red blood cells (RBCs) on a carrier margination in relation to RBC concentration (hematocrit) and pressure drop. As model drug carriers, fluorescent polymeric nanoparticles (FNPs) were chosen, which were obtained by using as starting material a pegylated polylactic acid–polyaspartamide copolymer. The latter was synthesized by derivatization of α,β-poly(N-2-hydroxyethyl)-d,l-aspartamide (PHEA) with Rhodamine (RhB), polylactic acid (PLA) and then poly(ethyleneglycol) (PEG) chains. It was found that the carrier concentration near the wall increases with increasing pressure drop, independently of RBC concentration, and that the tendency for FNP margination decreases with increasing hematocrit. This work highlights the importance of taking into account RBC–drug carrier interactions and physiological conditions in microcirculation when planning a drug delivery strategy based on systemically administered carriers. Full article
(This article belongs to the Special Issue Biomedical Applications of Polylactide (PLA) and its Copolymers)
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Open AccessArticle Biological Properties of Low-Toxic PLGA and PLGA/PHB Fibrous Nanocomposite Scaffolds for Osseous Tissue Regeneration. Evaluation of Potential Bioactivity
Molecules 2017, 22(11), 1852; doi:10.3390/molecules22111852
Received: 5 September 2017 / Revised: 19 October 2017 / Accepted: 24 October 2017 / Published: 28 October 2017
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Abstract
Abstracts: The aim of the study was to evaluate the biocompatibility and bioactivity of two new prototype implants for bone tissue regeneration made from biodegradable fibrous materials. The first is a newly developed poly(l-lactide-co-glycolide), (PLGA), and the second is a blend of
[...] Read more.
Abstracts: The aim of the study was to evaluate the biocompatibility and bioactivity of two new prototype implants for bone tissue regeneration made from biodegradable fibrous materials. The first is a newly developed poly(l-lactide-co-glycolide), (PLGA), and the second is a blend of PLGA with synthetic poly([R,S]-3-hydroxybutyrate) (PLGA/PHB). The implant prototypes comprise PLGA or PLGA/PHB nonwoven fabrics with designed pore structures to create the best conditions for cell proliferation. The bioactivity of the proposed implants was enhanced by introducing a hydroxyapatite material and a biologically active agent, namely, growth factor IGF1, encapsulated in calcium alginate microspheres. To assess the biocompatibility and bioactivity, allergenic tests and an assessment of the local reaction of bone tissue after implantation were performed. Comparative studies of local tissue response after implantation into trochanters for a period of 12 months were performed on New Zealand rabbits. Based on the results of the in vivo evaluation of the allergenic effects and the local tissue reaction 12 months after implantation, it was concluded that the two implant prototypes, PLGA + IGF1 and PLGA/PHB + IGF1, were characterized by high biocompatibility with the soft and bone tissues of the tested animals. Full article
(This article belongs to the Special Issue Biomedical Applications of Polylactide (PLA) and its Copolymers)
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Open AccessArticle Fabrication of Antimicrobial Peptide-Loaded PLGA/Chitosan Composite Microspheres for Long-Acting Bacterial Resistance
Molecules 2017, 22(10), 1637; doi:10.3390/molecules22101637
Received: 14 September 2017 / Revised: 23 September 2017 / Accepted: 25 September 2017 / Published: 29 September 2017
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Abstract
An antimicrobial decapeptide, KSL-W (KKVVFWVKFK-CONH2), which could maintain stable antimicrobial activity in saliva, has therefore been widely used to inhibit biofilm formation on teeth and prevent the growth of oral microorganisms for related infectious diseases treatment. In order to control the
[...] Read more.
An antimicrobial decapeptide, KSL-W (KKVVFWVKFK-CONH2), which could maintain stable antimicrobial activity in saliva, has therefore been widely used to inhibit biofilm formation on teeth and prevent the growth of oral microorganisms for related infectious diseases treatment. In order to control the release of KSL-W for long-term bacterial resistance, KSL-W-loaded PLGA/chitosan composite microspheres (KSL/PLGA/CS MSs) were prepared by electrospraying and combined crosslinking-emulsion methods. Different formulations of microspheres were characterized as to surface morphology, size distribution, encapsulation efficiency, in vitro drug release, and antimicrobial activity. Antibacterial experiment demonstrated the prolonged antimicrobial and inhibitory effects of KSL/PLGA/CS MSs on oral bacteria. Moreover, the cell proliferation assay proved that the released KSL-W antibacterial dosage had no cytotoxicity to the growth of osteoblast MC3T3-E1. Thus, our study suggested that the KSL-W-loaded PLGA/CS composite microspheres may have potentially therapeutic applications as an effective drug delivery system in the treatment of oral infectious diseases such as periodontitis and periodontitis, and also within bone graft substitutes for alveolar bone augmentation. Full article
(This article belongs to the Special Issue Biomedical Applications of Polylactide (PLA) and its Copolymers)
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Open AccessArticle Preventing Surgical Site Infections Using a Natural, Biodegradable, Antibacterial Coating on Surgical Sutures
Molecules 2017, 22(9), 1570; doi:10.3390/molecules22091570
Received: 17 August 2017 / Accepted: 16 September 2017 / Published: 19 September 2017
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Abstract
Surgical site infections (SSIs) are one of the most common nosocomial infections, which can result in serious complications after surgical interventions. Foreign materials such as implants or surgical sutures are optimal surfaces for the adherence of bacteria and subsequent colonization and biofilm formation.
[...] Read more.
Surgical site infections (SSIs) are one of the most common nosocomial infections, which can result in serious complications after surgical interventions. Foreign materials such as implants or surgical sutures are optimal surfaces for the adherence of bacteria and subsequent colonization and biofilm formation. Due to a significant increase in antibiotic-resistant bacterial strains, naturally occurring agents exhibiting antibacterial properties have great potential in prophylactic therapies. The aim of this study was to develop a coating for surgical sutures consisting of the antibacterial substance totarol, a naturally occurring diterpenoid isolated from Podocarpus totara in combination with poly(lactide-co-glycolide acid) (PLGA) as a biodegradable drug delivery system. Hence, non-absorbable monofilament and multifilament sutures were coated with solutions containing different amounts and ratios of totarol and PLGA, resulting in a smooth, crystalline coating. Using an agar diffusion test (ADT), it became evident that the PLGA/totarol-coated sutures inhibited the growth of Staphylococcus aureus over a period of 15 days. A 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay showed that the coated sutures were not cytotoxic to murine fibroblasts. Overall, the data indicates that our innovative, biodegradable suture coating has the potential to reduce the risk of SSIs and postoperative biofilm-formation on suture material without adverse effects on tissue. Full article
(This article belongs to the Special Issue Biomedical Applications of Polylactide (PLA) and its Copolymers)
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Open AccessArticle Research on a Nonwoven Fabric Made from Multi-Block Biodegradable Copolymer Based on l-Lactide, Glycolide, and Trimethylene Carbonate with Shape Memory
Molecules 2017, 22(8), 1325; doi:10.3390/molecules22081325
Received: 18 July 2017 / Revised: 1 August 2017 / Accepted: 8 August 2017 / Published: 10 August 2017
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Abstract
The presented paper concerns scientific research on processing a poly(lactide-co-glycolide-co-trimethylene carbonate) copolymer (PLLAGLTMC) with thermally induced shape memory and a transition temperature around human body temperature. The material in the literature called terpolymer was used to produce smart, nonwoven
[...] Read more.
The presented paper concerns scientific research on processing a poly(lactide-co-glycolide-co-trimethylene carbonate) copolymer (PLLAGLTMC) with thermally induced shape memory and a transition temperature around human body temperature. The material in the literature called terpolymer was used to produce smart, nonwoven fabric with the melt blowing technique. Bioresorbable and biocompatible terpolymers with shape memory have been investigated for its medical applications, such as cardiovascular stents. There are several research studies on shape memory in polymers, but this phenomenon has not been widely studied in textile products made from shape memory polymers (SMPs). The current research aims to explore the characteristics of the PLLAGLTMC nonwoven fabric in detail and the mechanism of its shape memory behavior. In this study, the nonwoven fabric was subjected to thermo-mechanical, morphological, and shape memory analysis. The thermo-mechanical and structural properties were investigated by means of differential scanning calorimetry, dynamic mechanical analysis, scanning electron microscopic examination, and mercury porosimetry measurements. Eventually, the gathered results confirmed that the nonwoven fabric possessed characteristics that classified it as a smart material with potential applications in medicine. Full article
(This article belongs to the Special Issue Biomedical Applications of Polylactide (PLA) and its Copolymers)
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Open AccessArticle Development of Antimicrobial Packaging Film Made from Poly(Lactic Acid) Incorporating Titanium Dioxide and Silver Nanoparticles
Molecules 2017, 22(7), 1170; doi:10.3390/molecules22071170
Received: 15 June 2017 / Revised: 11 July 2017 / Accepted: 11 July 2017 / Published: 13 July 2017
Cited by 1 | PDF Full-text (4068 KB) | HTML Full-text | XML Full-text
Abstract
Polylactide (PLA)/nano-TiO2 and PLA/nano-TiO2/nano-Ag blends films were prepared by a solvent volatilization method. Compared to pure PLA film, the nano-blend films have low water vapor permeability (WVP) and a poor transparency. With the increase of the NPs in the PLA,
[...] Read more.
Polylactide (PLA)/nano-TiO2 and PLA/nano-TiO2/nano-Ag blends films were prepared by a solvent volatilization method. Compared to pure PLA film, the nano-blend films have low water vapor permeability (WVP) and a poor transparency. With the increase of the NPs in the PLA, the tensile strength (TS) and elastic modulus (EM) decreased, while the elongation at break (ε) increased. SEM analysis indicated a rougher cross-section of the nano-blend films. According to the FTIR analysis, no new chemical bonds were formed in the nano-blend films. By using DSC to examine the crystallization and melting behavior, the result shows that the NPs have no effect on the glass transition (Tg) and melting temperature (Tm), but they caused an increase on the cold crystallization (Tc) and crystallinity (Xc). TGA results show that the addition of nanoparticles significantly improved the thermal stability. The PLA nano-blend films show a good antimicrobial activity against. E. coli and Listeria monocytogenes. Most important, we carried out migration tests, and verified that the release of NPs from the nano-blend films was within the standard limits. Full article
(This article belongs to the Special Issue Biomedical Applications of Polylactide (PLA) and its Copolymers)
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Open AccessArticle Pamidronate-Conjugated Biodegradable Branched Copolyester Carriers: Synthesis and Characterization
Molecules 2017, 22(7), 1063; doi:10.3390/molecules22071063
Received: 8 May 2017 / Accepted: 22 June 2017 / Published: 26 June 2017
PDF Full-text (2814 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
The need for development of comprehensive therapeutic systems, (e.g., polymer-apatite composites) as a bone substitute material has previously been highlighted in many scientific reports. The aim of this study was to develop a new multifunctional composite based on hydroxyapatite porous granules doped with
[...] Read more.
The need for development of comprehensive therapeutic systems, (e.g., polymer-apatite composites) as a bone substitute material has previously been highlighted in many scientific reports. The aim of this study was to develop a new multifunctional composite based on hydroxyapatite porous granules doped with selenite ions (SeO32−) and a biodegradable branched copolymer-bisphosphonate conjugate as a promising bone substitute material for patients with bone tumours or bone metastasis. A series of biodegradable and branched copolymer matrices, adequate for delivery of bisphosphonate in the bone-deficient area were synthesized and physico-chemically and biologically (cyto- and genotoxicity assays) characterized. Branched copolymers were obtained using a hyperbranched bis-MPA polyester-16-hydroxyl initiator and Sn(Oct)2, a (co)catalyst of the ring-opening polymerization (ROP) of l,l-lactide (LLA) and ε-caprolactone (CL). A new amide bond was formed between the hydroxyl end groups of the synthesized copolymer carriers and an amine group of pamidronate (PAM)—the drug inhibiting bone resorption and osteoclast activity in bone. The dependence of the physico-chemical properties of the copolymer matrices on the kinetic release of PAM from the synthesized branched copolymer conjugate-coated hydroxyapatite granules doped with selenite ions was observed. Moreover, the correlation of these results with the hydrolytic degradation data of the synthesized matrices was evidenced. Therefore, the developed composite porous hydroxyapatite doped with SeO32− ions/biodegradable copolymer-PAM conjugate appears most attractive as a bone substitute material for cancer patients. Full article
(This article belongs to the Special Issue Biomedical Applications of Polylactide (PLA) and its Copolymers)
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