Abstract:
:A novel class of multiblock poly(epsilon-caprolactone)-based polymers containing hydrophilic trioxyethylene segments and potentially relevant to the delivery of drugs is described in this work. L-phenylalanine residues may also be inserted into the hydrophilic blocks to generate peptide bonds susceptible to enzymatic attack. The investigated polymers were poly(ether-ester-amide)s (PEEAs) obtained by a two-step polymerization procedure from OH-end capped low molecular weight poly(epsilon-caprolactone), sebacoyl chloride and either 4,7,10-trioxa-1,13-tridecanediamine (PEEA1) or 1,13-di(L-phenylalaninamido)-4,7,10-trioxatridecane (PEEA2). PEEAs were characterized by 1H-NMR spectroscopy, differential scanning calorimetry, gel permeation chromatography and were tested for their suitability in producing microspheres. Particles obtained by the single emulsion-solvent evaporation technique were regular and smooth (SEM analysis) showing a monomodal distribution of dimensions. To assess the potentiality of PEEAs in the oral delivery of drugs, three model compounds with different pKa and solubilities--diclofenac, nicardipine and dicumarol--were encapsulated within PEEA microspheres. For the sake of comparison, microspheres prepared from poly(epsilon-caprolactone) (PCL) with a molecular weight similar to PEEAs were also prepared and tested. The release of diclofenac from all the microspheres was very rapid (100% released within 2 h) whereas nicardipine release was slower and biphasic. The initial phase approximated a near zero-order release, being the fraction of nicardipine released after 8 h from PEEA microspheres higher with respect to PCL particles (about 70 vs. 30%). This result was ascribed to the lower crystallinity of PEEAs with respect to PCL which results in a facilitated access of water molecules through the polymer matrix. The lipophilic-unionizable dicumarol was released from PEEA microspheres at a very slow rate. Therefore, dicumarol-loaded PEEA2 microspheres allowed the study of the influence on the release rate of the insertion into the polymer chain of enzymatically degradable bonds. PEEA2 microspheres released dicumarol at the same rate in a medium with or without the proteolitic enzyme alpha-chymotrypsin. Although the insertion of an isolated amino acid was not sufficient to confer enzyme susceptibility to the polymer, the distinctive properties of PEEAs make their use very attractive in the field of controlled release.
journal_name
Biomaterialsjournal_title
Biomaterialsauthors
Barbato F,La Rotonda MI,Maglio G,Palumbo R,Quaglia Fdoi
10.1016/s0142-9612(00)00291-xkeywords:
subject
Has Abstractpub_date
2001-06-01 00:00:00pages
1371-8issue
11eissn
0142-9612issn
1878-5905pii
S014296120000291Xjournal_volume
22pub_type
杂志文章相关文献
BIOMATERIALS文献大全abstract::Hyaluronan (HL), a naturally occurring glycosaminoglycan, has been chemically modified through the esterification of its carboxylic groups with different types of alcohol. The physico-chemical properties of these new biopolymers allow the preparation of many biomaterials which may be used in several medical applicatio...
journal_title:Biomaterials
pub_type: 杂志文章
doi:10.1016/0142-9612(93)90160-4
更新日期:1993-12-01 00:00:00
abstract::Osteogenic agents, such as bone morphogenetic protein-2 (BMP-2), can stimulate the degradation as well as the formation of bone. Hence, they could impair the osteoconductivity of functionalized implant surfaces. We assessed the effects of BMP-2 and its mode of delivery on the osteoconductivity of dental implants with ...
journal_title:Biomaterials
pub_type: 杂志文章
doi:10.1016/j.biomaterials.2007.02.003
更新日期:2007-06-01 00:00:00
abstract::Loosening of the femoral component in a total hip arthroplasty with concomitant bone loss can pose a problem for revision surgery due to inadequate structure in the remaining femur. While impaction allografting has shown promise, it has also shown serious complications, especially with moderate to severe bone loss. It...
journal_title:Biomaterials
pub_type: 杂志文章
doi:10.1016/j.biomaterials.2005.05.062
更新日期:2005-12-01 00:00:00
abstract::A novel asymmetric chitosan membrane has been prepared by immersion-precipitation phase-inversion method and evaluated as wound covering. This new type of chitosan wound dressing which consists of skin surface on top-layer supported by a macroporous sponge-like sublayer was designed. The thickness of the dense skin su...
journal_title:Biomaterials
pub_type: 杂志文章
doi:10.1016/s0142-9612(00)00167-8
更新日期:2001-01-01 00:00:00
abstract::A limitation with the use of polymers as stent matrices is their inherent mechanical weakness. In this study, a polymeric stent, made from chitosan-based films fixed by genipin which has a cyclic molecular structure, was developed (the genipin stent). The mechanical properties of the genipin stent were investigated; i...
journal_title:Biomaterials
pub_type: 杂志文章
doi:10.1016/j.biomaterials.2009.06.039
更新日期:2009-10-01 00:00:00
abstract::Our focus was to develop a three-dimensional (3D) human dynamic in vitro tissue model that mimics the natural microenvironment of the small intestine. We co-cultured human Caco-2 cells with primary-isolated human microvascular endothelial cells (hMECs) on decellularized porcine jejunal segments within a custom-made dy...
journal_title:Biomaterials
pub_type: 杂志文章
doi:10.1016/j.biomaterials.2011.06.035
更新日期:2011-10-01 00:00:00
abstract::Carbon nanotubes have shown great potential in various areas of biomedicine. Herein, we synthesize a series of amphiphilic polymers by anchoring polyethylene glycol (PEG) of different lengths at various densities on poly(maleic anhydride-alt-1-octadecene) (PMHC(18)). The blood circulation and biodistribution of those ...
journal_title:Biomaterials
pub_type: 杂志文章
doi:10.1016/j.biomaterials.2010.08.096
更新日期:2011-01-01 00:00:00
abstract::The porous TiO2/perlite composite Ecopore is a synthetic biomaterial with possible clinical application in bone substitution. In our previous work, we demonstrated that surface modification of Ecopore with fibronectin (FN) enhanced spreading and growth of human osteoblasts in vitro. In the present study, we implanted ...
journal_title:Biomaterials
pub_type: 杂志文章
doi:10.1016/j.biomaterials.2005.08.001
更新日期:2006-03-01 00:00:00
abstract::Chitosan (CHT)/poly(ɛ-caprolactone) (PCL) blend 3D fiber-mesh scaffolds were studied as possible support structures for articular cartilage tissue (ACT) repair. Micro-fibers were obtained by wet-spinning of three different polymeric solutions: 100:0 (100CHT), 75:25 (75CHT) and 50:50 (50CHT) wt.% CHT/PCL, using a commo...
journal_title:Biomaterials
pub_type: 杂志文章
doi:10.1016/j.biomaterials.2010.09.073
更新日期:2011-02-01 00:00:00
abstract::Rare-earth upconversion nanoparticles (UCNP) which can absorb low-energy photons and emit high energy photons have attracted great interest not only because of their unique application in upconversion luminescence imaging, but also because they can be used as ideal building blocks for multimodal bioimaging probes. Imp...
journal_title:Biomaterials
pub_type: 杂志文章
doi:10.1016/j.biomaterials.2011.07.053
更新日期:2011-11-01 00:00:00
abstract::We have developed a crosslinked hyaluronic acid (HA) film with DNA incorporated within its structure and have characterized this system for its efficacy in sustained transferring of a vector encoding mouse hyaluronan synthase 2 (Has2). Analysis of the DNA release kinetics indicated that the HA films degraded when trea...
journal_title:Biomaterials
pub_type: 杂志文章
doi:10.1016/j.biomaterials.2004.05.015
更新日期:2005-05-01 00:00:00
abstract::Arterial catheterization is one of the most frequently performed inpatient diagnostic and therapeutic procedures in the development countries. Complications may occur after any catheterization from inadequate hemostasis, particularly in the setting of aggressive anticoagulation. This study suggests that microcrystalli...
journal_title:Biomaterials
pub_type: 杂志文章
doi:10.1016/s0142-9612(98)00060-x
更新日期:1998-08-01 00:00:00
abstract::To broaden the clinical application of cartilage regenerative medicine, we should develop an implant-type tissue-engineered cartilage with firmness and 3-D structure. For that, we attempted to use a porous biodegradable polymer scaffold in the combination with atelocollagen hydrogel, and optimized the structure and co...
journal_title:Biomaterials
pub_type: 杂志文章
doi:10.1016/j.biomaterials.2010.02.028
更新日期:2010-06-01 00:00:00
abstract::Si, Mg-substituted hydroxyapatites, alone and co-substituted, have been prepared to obtain biomaterials having an improved biocompatibility. From FT-IR, XRD and ICP analyses, it was confirmed that single phases of hydroxyapatite substituted by Si alone or co-substituted by Si, Mg. The XRD data indicated the absence of...
journal_title:Biomaterials
pub_type: 杂志文章
doi:10.1016/s0142-9612(02)00523-9
更新日期:2003-04-01 00:00:00
abstract::In regenerative medicine, accumulating evidence demonstrates that the property of substrates monitors neural stem cells behavior. However, how stem cells sense and interpret biochemical and topographical cues remains elusive. This study aimed to explore the mechanism how nanofibrous scaffold modulated stem cells behav...
journal_title:Biomaterials
pub_type: 杂志文章
doi:10.1016/j.biomaterials.2011.05.075
更新日期:2011-10-01 00:00:00
abstract::Oxidative stress is commonly existed in bone degenerative disease (osteoarthritis, osteoporosis etc.) and some antioxidants had great potential to enhance osteogenesis. In this study, we aim to investigate the anti-oxidative properties of various TiO2 nanotubes (TNTs) so to screen the desirable size for improved osteo...
journal_title:Biomaterials
pub_type: 杂志文章
doi:10.1016/j.biomaterials.2018.03.024
更新日期:2018-06-01 00:00:00
abstract::Cationic polymer PEI-CyD is doped with Nd by plasma technology to produce the gene vector: Nd@PEI-CyD. Luciferase expression and EGFP transfection experiments performed in vitro reveal that Nd@PEI-CyD has significantly higher transfection efficiency than lipofectamine 2000 and PEI-CyD and the mechanism is studied and ...
journal_title:Biomaterials
pub_type: 杂志文章
doi:10.1016/j.biomaterials.2013.09.069
更新日期:2014-01-01 00:00:00
abstract::Using laser Raman microprobe spectroscopy, we have characterized the degree of hydroxylation and the state of atomic order of several natural and synthetic calcium phosphate phases, including apatite of biological (human bone, heated human bone, mouse bone, human and boar dentin, and human and boar enamel), geological...
journal_title:Biomaterials
pub_type: 杂志文章
doi:10.1016/s0142-9612(03)00487-3
更新日期:2004-01-01 00:00:00
abstract::Tissue engineering combined with gene therapy represents a promising approach for bone regeneration. The Hypoxia-inducible factor-1α (HIF-1α) gene is a pivotal regulator of vascular reactivity and angiogenesis. Our recent study has showed that HIF-1α could promote osteogenesis of bone mesenchymal stem cells (BMSCs) us...
journal_title:Biomaterials
pub_type: 杂志文章
doi:10.1016/j.biomaterials.2011.09.005
更新日期:2011-12-01 00:00:00
abstract::The anterior cruciate ligament (ACL) is the most commonly injured intra-articular ligament of the knee, and limitations in existing reconstruction grafts have prompted an interest in tissue engineered solutions. Previously, we reported on a tissue-engineered ACL scaffold fabricated using a novel, three-dimensional bra...
journal_title:Biomaterials
pub_type: 杂志文章
doi:10.1016/j.biomaterials.2004.11.050
更新日期:2005-08-01 00:00:00
abstract::Cutaneous melanoma is an increasingly common and potentially lethal malignancy of melanocytes, the melanin producing cells normally located in the basal layer of the skin epidermis. Despite major advances in cancer chemotherapeutics and immunotherapy, the success in treating metastatic melanoma remains poor. The notio...
journal_title:Biomaterials
pub_type: 杂志文章
doi:10.1016/j.biomaterials.2011.08.056
更新日期:2011-12-01 00:00:00
abstract::Materials for orthopaedic implants can fail for several combined reasons: corrosion, fatigue and wear for metals, wear and creep for polymers, fracture for ceramics. Some typical cases are analysed and it is demonstrated that ion implantation improves metals and polymers used for joint prosthesis. Implantations of nit...
journal_title:Biomaterials
pub_type: 杂志文章
doi:
更新日期:1990-07-01 00:00:00
abstract::It is estimated that 4 to 5 million people are currently co-infected with Human Immunodeficiency Virus (HIV) and Hepatitis C Virus (HCV). HIV/HCV co-infection is associated with unique health risks including increased hepatotoxicity of antiretrovirals, accelerated progression of HCV and liver diseases. The standard in...
journal_title:Biomaterials
pub_type: 杂志文章
doi:10.1016/j.biomaterials.2013.01.026
更新日期:2013-05-01 00:00:00
abstract::Nitric oxide (NO) possesses various functions in cardiovascular diseases; however, due to an extremely short half-life and low bioavailability, its therapeutic application is limited. In inflamed tissues, overproduced reactive oxygen species (ROS) rapidly react with the endogenous NO, reducing its bioavailability. Her...
journal_title:Biomaterials
pub_type: 杂志文章
doi:10.1016/j.biomaterials.2018.03.023
更新日期:2018-06-01 00:00:00
abstract::Angiogenesis plays a prominent role in cancer progression. Anti-angiogenic therapy therefore, either alone or in combination with conventional cytotoxic therapy, offers a promising therapeutic approach. Paclitaxel (PTX) is a widely-used potent cytotoxic drug that also exhibits anti-angiogenic effects at low doses. How...
journal_title:Biomaterials
pub_type: 杂志文章
doi:10.1016/j.biomaterials.2011.01.073
更新日期:2011-05-01 00:00:00
abstract::Recent studies suggest that bone marrow stromal cells are a potential source of osteoblasts and chondrocytes and can be used to regenerate damaged tissues using a tissue-engineering (TE) approach. However, these strategies require the use of an appropriate scaffold architecture that can support the formation de novo o...
journal_title:Biomaterials
pub_type: 杂志文章
doi:10.1016/j.biomaterials.2006.07.034
更新日期:2006-12-01 00:00:00
abstract::We have synthesized a series of coumarins (1-3) that can emit fluorescence in a turn-on manner through a Michael-type reaction with thiol-containing compounds. The only difference among the coumarins is the position of a carboxyl group on its benzene ring moiety near the double-bond conjugated coumarin. Their selectiv...
journal_title:Biomaterials
pub_type: 杂志文章
doi:10.1016/j.biomaterials.2012.08.009
更新日期:2012-11-01 00:00:00
abstract::Pancreatic cancer has the worst prognosis of all cancers due to disease aggressiveness and paucity of early detection platforms. We developed biomaterial scaffolds that recruit metastatic tumor cells and reflect the immune dysregulation of native metastatic sites. While this platform has shown promise in orthotopic br...
journal_title:Biomaterials
pub_type: 杂志文章
doi:10.1016/j.biomaterials.2020.120632
更新日期:2020-12-23 00:00:00
abstract::Silver nanoparticles (AgNPs) have anti-cancer effect. However, whether and how these particles could inhibit the growth of acute myeloid leukemia (AML) cells is unclear. In the present study, we prepared AgNPs with various sizes and investigated their cytotoxic effect on AML cells. We found that AgNPs could inhibit th...
journal_title:Biomaterials
pub_type: 杂志文章
doi:10.1016/j.biomaterials.2013.07.015
更新日期:2013-10-01 00:00:00
abstract::The present study deals with the effect of the type and chemical character of incorporated polyester (polyether blocks) on the hydrolytic stability of different types of polyurethane medical adhesive dressings. Diffusion parameters of the investigated polyurethane adhesives, giving information concerning the chemical ...
journal_title:Biomaterials
pub_type: 杂志文章
doi:10.1016/0142-9612(94)90198-8
更新日期:1994-01-01 00:00:00