共查询到20条相似文献,搜索用时 281 毫秒
1.
Kayla Belanger Tony M. Dinis Sami Taourirt Guillaume Vidal David L. Kaplan Christopher Egles 《Macromolecular bioscience》2016,16(4):472-481
The repair of large crushed or sectioned segments of peripheral nerves remains a challenge in regenerative medicine due to the complexity of the biological environment and the lack of proper biomaterials and architecture to foster reconstruction. Traditionally such reconstruction is only achieved by using fresh human tissue as a surrogate for the absence of the nerve. However, recent focus in the field has been on new polymer structures and specific biofunctionalization to achieve the goal of peripheral nerve regeneration by developing artificial nerve prostheses. This review presents various tested approaches as well their effectiveness for nerve regrowth and functional recovery.
2.
Reactive oxygen species (ROS) play important roles in cell signaling pathways, while increased production of ROS may disrupt cellular homeostasis, giving rise to oxidative stress and a series of diseases. Utilizing these cell‐generated species as triggers for selective tuning polymer structures and properties represents a promising methodology for disease diagnosis and treatment. Recently, significant progress has been made in fabricating biomaterials including nanoparticles and macroscopic networks to interact with this dynamic physiological condition. These ROS‐responsive platforms have shown potential in a range of biomedical applications, such as cancer targeted drug delivery systems, cell therapy platforms for inflammation related disease, and so on.
3.
Polypyrrole/Alginate Hybrid Hydrogels: Electrically Conductive and Soft Biomaterials for Human Mesenchymal Stem Cell Culture and Potential Neural Tissue Engineering Applications 下载免费PDF全文
Sumi Yang LindyK. Jang Semin Kim Jongcheol Yang Kisuk Yang Seung‐Woo Cho Jae Young Lee 《Macromolecular bioscience》2016,16(11):1653-1661
Electrically conductive biomaterials that can efficiently deliver electrical signals to cells or improve electrical communication among cells have received considerable attention for potential tissue engineering applications. Conductive hydrogels are desirable particularly for neural applications, as they can provide electrical signals and soft microenvironments that can mimic native nerve tissues. In this study, conductive and soft polypyrrole/alginate (PPy/Alg) hydrogels are developed by chemically polymerizing PPy within ionically cross‐linked alginate hydrogel networks. The synthesized hydrogels exhibit a Young's modulus of 20–200 kPa. Electrical conductance of the PPy/Alg hydrogels could be enhanced by more than one order of magnitude compared to that of pristine alginate hydrogels. In vitro studies with human bone marrow‐derived mesenchymal stem cells (hMSCs) reveal that cell adhesion and growth are promoted on the PPy/Alg hydrogels. Additionally, the PPy/Alg hydrogels support and greatly enhance the expression of neural differentiation markers (i.e., Tuj1 and MAP2) of hMSCs compared to tissue culture plate controls. Subcutaneous implantation of the hydrogels for eight weeks induces mild inflammatory reactions. These soft and conductive hydrogels will serve as a useful platform to study the effects of electrical and mechanical signals on stem cells and/or neural cells and to develop multifunctional neural tissue engineering scaffolds.
4.
Formation of Highly Aligned Collagen Nanofibers by Continuous Cyclic Stretch of a Collagen Hydrogel Sheet 下载免费PDF全文
A collagen sheet with highly aligned collagen fibers is fabricated by continuous cyclic stretch. The rearrangement of the collagen fibers depends on the different process parameters of the cyclic stretch, including magnitude, frequency, and period of stretch. The collagen fibers are aligned perpendicularly to the direction of the stretch. Corneal stromal cells and smooth muscle cells cultivated on the highly aligned collagen sheet show alignment along the collagen fibers without the stretch during culture. Thus, the sheet can be a suitable scaffold for use in regenerative medicine.
5.
RGDS‐ and SIKVAVS‐Modified Superporous Poly(2‐hydroxyethyl methacrylate) Scaffolds for Tissue Engineering Applications 下载免费PDF全文
Hana Macková Zdeněk Plichta Vladimír Proks Ilya Kotelnikov Jan Kučka Helena Hlídková Daniel Horák Šárka Kubinová Klára Jiráková 《Macromolecular bioscience》2016,16(11):1621-1631
Three‐dimensional hydrogel supports for mesenchymal and neural stem cells (NSCs) are promising materials for tissue engineering applications such as spinal cord repair. This study involves the preparation and characterization of superporous scaffolds based on a copolymer of 2‐hydroxyethyl and 2‐aminoethyl methacrylate (HEMA and AEMA) crosslinked with ethylene dimethacrylate. Ammonium oxalate is chosen as a suitable porogen because it consists of needle‐like crystals, allowing their parallel arrangement in the polymerization mold. The amino group of AEMA is used to immobilize RGDS and SIKVAVS peptide sequences with an N‐γ‐maleimidobutyryloxy succinimide ester linker. The amount of the peptide on the scaffold is determined using 125I radiolabeled SIKVAVS. Both RGDS‐ and SIKVAVS‐modified poly(2‐hydroxyethyl methacrylate) scaffolds serve as supports for culturing human mesenchymal stem cells (MSCs) and human fetal NSCs. The RGDS sequence is found to be better for MSC and NSC proliferation and growth than SIKVAVS.
6.
A Silk Fibroin and Peptide Amphiphile‐Based Co‐Culture Model for Osteochondral Tissue Engineering 下载免费PDF全文
Anıl S. Çakmak David L. Kaplan Menemşe Gümüşderelioğlu 《Macromolecular bioscience》2016,16(8):1212-1226
New biomaterials with the properties of both bone and cartilage extracellular matrices (ECM) should be designed and used with co‐culture systems to address clinically applicable osteochondral constructs. Herein, a co‐culture model is described based on a trilayered silk fibroin‐peptide amphiphile (PA) scaffold cultured with human articular chondrocytes (hACs) and human bone marrow mesenchymal stem cells (hBMSCs) in an osteochondral cocktail medium for the cartilage and bone sides, respectively. The presence of hACs in the co‐cultures significantly increases the osteogenic differentiation potential of hBMSCs based on ALP activity, RT‐PCR for osteogenic markers, calcium analyses, and histological stainings, whereas hACs produces a significant amount of glycosaminoglycans (GAGs) for the cartilage region, even in the absence of growth factor TGF‐β family in the co‐culture medium. This trilayered scaffold with trophic effects offers a promising strategy for the study of osteochondral defects.
7.
Stéphanie Metzger Ulrich Blache Philipp S. Lienemann Maria Karlsson Franz E. Weber Wilfried Weber Martin Ehrbar 《Macromolecular bioscience》2016,16(11):1703-1713
Engineering in vitro tissue mimetics that resemble the corresponding living tissues requires the 3D arrangement of tissue progenitor cells and their differentiation by localized growth factor (GF) signaling cues. Recent technological advances open a large field of possibilities for the creation of complex GF arrangements. Additionally, cell‐instructive biomaterials, which bind GFs by various mechanisms and release them with different kinetics depending on binding affinity, have become available. This paper describes the development of a matrix metalloproteinase (MMP)‐degradable streptavidin‐based linker module, which allows the release of immobilized GFs from synthetic biomimetic poly(ethylene glycol) hydrogels independently of the hydrogel degradation. The MMP‐sensitive streptavidin linker is shown to efficiently bind biotinylated molecules, and as proof of concept, bone morphogenetic protein‐2 (BMP‐2) delivery via the MMP‐degradable linker is used to induce osteogenic differentiation in C2C12 cells and mesenchymal stem cells. The results show a significantly increased net effect of proteolytically releasable BMP‐2 in comparison to stably immobilized and soluble BMP‐2. This study indicates that a GF delivery system directly responsive to cellular activity can have important implications for the synthesis of tissue mimetics and regenerative medicine, as it can influence the availability, the localization of effects, as well as efficacy of employed GFs.
8.
Differentiation of Human Mesenchymal Stem Cells Toward Quality Cartilage Using Fibrinogen‐Based Nanofibers 下载免费PDF全文
Jeremy Forget Firas Awaja Dencho Gugutkov Juhan Gustavsson Gloria Gallego Ferrer Tatiana Coelho‐Sampaio Camila Hochman‐Mendez Manuel Salmeron‐Sánchez George Altankov 《Macromolecular bioscience》2016,16(9):1348-1359
9.
Zwitterionic Cellulose Carbamate with Regioselective Substitution Pattern: A Coating Material Possessing Antimicrobial Activity 下载免费PDF全文
Thomas Elschner Claudia Lüdecke Diana Kalden Martin Roth Bettina Löffler Klaus D. Jandt Thomas Heinze 《Macromolecular bioscience》2016,16(4):522-534
A polyzwitterion is synthesized by regioselective functionalization of cellulose possessing a uniform charge distribution. The positively charged ammonium group is present at position 6, while the negative charge of carboxylate is located at positions 2 and 3 of the repeating unit. The molecular structure of the biopolymer derivative is proved by NMR spectroscopy. This cellulose‐based zwitterion is applied to several support materials by spin‐coating and characterized by means of atomic force microscope, contact angle measurements, ellipsometry, and X‐ray photoelectron spectroscopy. The coatings possess antimicrobial activity depending on the support materials (glass, titanium, tissue culture poly(styrene)) as revealed by confocal laser scanning microscopy and live/dead staining.
10.
Ferdia Bates María Concepción Cela‐Pérez Kal Karim Sergey Piletsky José Manuel López‐Vilariño 《Macromolecular bioscience》2016,16(8):1170-1174
Molecularly Imprinted Polymers (MIPs) are highly advantageous in the field of analytical chemistry. However, interference from secondary molecules can also impede capture of a target by a MIP receptor. This greatly complicates the design process and often requires extensive laboratory screening which is time consuming, costly, and creates substantial waste products. Herein, is presented a new technique for screening of “virtually imprinted receptors” for rebinding of the molecular template as well as secondary structures, correlating the virtual predictions with experimentally acquired data in three case studies. This novel technique is particularly applicable to the evaluation and prediction of MIP receptor specificity and efficiency in complex aqueous systems.
11.
Biosensing is an important and rapidly developing field, with numerous potential applications in health care, food processing, and environmental control. Polymer–graphene nanocomposites aim to leverage the unique, attractive properties of graphene by combining them with those of a polymer matrix. Molecular imprinted polymers, in particular, offer the promise of artificial biorecognition elements. A variety of polymers, including intrinsically conducting polymers (polyaniline, polypyrrole), bio‐based polymers (chitosan, polycatechols), and polycationic polymers (poly(diallyldimethylammonium chloride), polyethyleneimine), have been utilized as matrices for graphene‐based nanofillers, yielding sensitive biosensors for various biomolecules, such as proteins, nucleic acids, and small molecules.
12.
Visible Light and pH Responsive Polymer‐Coated Mesoporous Silica Nanohybrids for Controlled Release 下载免费PDF全文
Guojie Wang Jie Dong Tingting Yuan Juchen Zhang Lei Wang Hao Wang 《Macromolecular bioscience》2016,16(7):990-994
A visible light and pH responsive anticancer drug delivery system based on polymer‐coated mesoporous silica nanoparticles (MSNs) has been developed. Perylene‐functionalized poly(dimethylaminoethyl methacrylates) sensitive to visible light and pH are electrostatically attached on the surface of MSNs to seal the nanopores. Stimulation of visible light and acid can unseal the nanopores to induce controlled drug release from the MSNs. More interestingly, the release can be enhanced under the combined stimulation of the dual‐stimuli. The synergistic effect of visible light and acid stimulation on the efficient release of anticancer drugs from the nanohybrids endows the system with great potential for cancer therapy.
13.
Switching the Stiffness of Polyelectrolyte Assembly by Light to Control Behavior of Supported Cells 下载免费PDF全文
Sviatlana A. Ulasevich Nadzeya Brezhneva Yulia Zhukova Helmuth Möhwald Peter Fratzl Felix H. Schacher Dmitry V. Sviridov Daria V. Andreeva Ekaterina V. Skorb 《Macromolecular bioscience》2016,16(10):1422-1431
Polyelectrolyte block copolymer micelles assembled thin film is switched in response to local photocatalytic reactions on titanium dioxide, resulting in a layer of variable height, stiffness in response to visible light irradiation. Preosteoblasts migrate toward stiffer side of the substrates.
14.
Development of an Injectable Calcium Phosphate/Hyaluronic Acid Microparticles System for Platelet Lysate Sustained Delivery Aiming Bone Regeneration 下载免费PDF全文
Pedro S. Babo Vítor E. Santo Manuela E. Gomes Rui L. Reis 《Macromolecular bioscience》2016,16(11):1662-1677
Despite the biocompatibility and osteoinductive properties of calcium phosphate (CaP) cements their low biodegradability hampers full bone regeneration. Herein the incorporation of CaP cement with hyaluronic acid (HAc) microparticles loaded with platelet lysate (PL) to improve the degradability and biological performance of the cements is proposed. Cement formulations incorporating increasing weight ratios of either empty HAc microparticles or microparticles loaded with PL (10 and 20 wt%) are developed as well as cements directly incorporating PL. The direct incorporation of PL improves the mechanical properties of the plain cement, reaching values similar to native bone. Morphological analysis shows homogeneous particle distribution and high interconnectivity between the HAc microparticles. The cements incorporating PL (with or without the HAc microparticles) present a sustained release of PL proteins for up to 8 d. The sustained release of PL modulates the expression of osteogenic markers in seeded human adipose tissue derived stem cells, thus suggesting the stimulatory role of this hybrid system toward osteogenic commitment and bone regeneration applications.
15.
Two‐Phase Electrospinning to Incorporate Polyelectrolyte Complexes and Growth Factors into Electrospun Chitosan Nanofibers 下载免费PDF全文
Laura W. Place Maria Sekyi Julia Taussig Matt J. Kipper 《Macromolecular bioscience》2016,16(3):371-380
Growth factors are potent signaling proteins for tissue engineering, but they are susceptible to loss of activity when exposed to solvents used for polymer processing. This work explores preservation of fibroblast growth factor‐2 (FGF‐2) activity in chitosan nanofibers using two‐phase electrospinning via a compound coaxial needle and from a water‐in‐oil emulsion FGF‐2 in aqueous poly(vinyl alcohol) is added on either the inside (A/O) or the outside (O/A) of an organic chitosan phase, using the compound needle. FGF‐2 is further stabilized by complexation to heparin‐based nanoparticles. The emulsion method does not result in detectable incorporation of FGF‐2. The A/O fibers incorporate the highest amount of FGF‐2. Nanoparticle‐stabilized FGF‐2 in A/O nanofibers is most active toward bone‐marrow stromal cells.
16.
Poly‐l‐Lactic Acid Nanofiber–Polyamidoamine Hydrogel Composites: Preparation,Properties, and Preliminary Evaluation as Scaffolds for Human Pluripotent Stem Cell Culturing 下载免费PDF全文
Chiara Gualandi Nora Bloise Nicolò Mauro Paolo Ferruti Amedea Manfredi Maurilio Sampaolesi Anna Liguori Romolo Laurita Matteo Gherardi Vittorio Colombo Livia Visai Maria Letizia Focarete Elisabetta Ranucci 《Macromolecular bioscience》2016,16(10):1533-1544
Electrospun poly‐l ‐lactic acid (PLLA) nanofiber mats carrying surface amine groups, previously introduced by nitrogen atmospheric pressure nonequilibrium plasma, are embedded into aqueous solutions of oligomeric acrylamide‐end capped AGMA1, a biocompatible polyamidoamine with arg‐gly‐asp (RGD)‐reminiscent repeating units. The resultant mixture is finally cured giving PLLA‐AGMA1 hydrogel composites that absorb large amounts of water and, in the swollen state, are translucent, soft, and pliable, yet as strong as the parent PLLA mat. They do not split apart from each other when swollen in water and remain highly flexible and resistant, since the hydrogel portion is covalently grafted onto the PLLA nanofibers via the addition reaction of the surface amine groups to a part of the terminal acrylic double bonds of AGMA1 oligomers. Preliminary tested as scaffolds, the composites prove capable of maintaining short‐term undifferentiated cultures of human pluripotent stem cells in feeder‐free conditions.
17.
Acid Sensitive Polymeric Micelles Combining Folate and Bioreducible Conjugate for Specific Intracellular siRNA Delivery 下载免费PDF全文
Yanfang Yang Xuejun Xia Wujun Dong Hongliang Wang Lin Li Panpan Ma Wei Sheng Xueqing Xu Yuling Liu 《Macromolecular bioscience》2016,16(5):759-773
An efficiently siRNA transporting nanocarrier still remains to be developed. In this study, utilizing the dual stimulus of acid tumor extracellular environment and redox effect of glutathione in the cytosol, a new siRNA transporting system combining triple effects of folate targeting, acid sensitive polymer micelles, and bio‐reducible disulfide bond linked siRNA‐cell penetrating peptides (CPPs) conjugate is developed to suppress c‐myc gene expression of breast cancer (MCF‐7 cells) both in vitro and in vivo. Subsequent research demonstrates that the vesicle has particle size of about 100 nm and siRNA entrapment efficiency of approximately 80%. In vitro studies verified over 90% of encapsulated siRNA‐CPPs can be released and the vesicle shows higher cellular uptake in response to the tumorous zone. Determination of gene expression at both mRNA and protein levels indicates the constructed vesicle exhibited enhanced cancer cell apoptosis and improved therapeutic efficacy in vitro and in vivo.
18.
Cytocompatible,Photoreversible, and Self‐Healing Hydrogels for Regulating Bone Marrow Stromal Cell Differentiation 下载免费PDF全文
Lianlian Yu Kaige Xu Liangpeng Ge Wenbing Wan Ali Darabi Malcolm Xing Wen Zhong 《Macromolecular bioscience》2016,16(9):1381-1390
Photo‐crosslinking and self‐healing have received considerable attention for the design of intelligent materials. A novel photostimulated, self‐healing, and cytocompatible hydrogel system is reported. A coumarin methacrylate crosslinker is synthesized to modify the polyacrylamide‐based hydrogels. With the [2+2] cyclo‐addition of coumarin moieties, the hydrogels exhibit excellent self‐healing capacity when they are exposed to light with wavelengths at 280 and 365 nm, respectively. To enhance cell compatibility, a poly (amidoamine) crosslinker is also synthesized. Variations in light exposure times and irradiation wavelengths are found to alter the self‐healing property of the hydrogels. The hydrogels are shown to induce a regular cellular pattern. The hydrogels are used to regulate bone marrow stromal cells differentiation. The relative mRNA expressions are recorded to monitor the osteogenic differentiation of the cells.
19.
Cell‐Free HA‐MA/PLGA Scaffolds with Radially Oriented Pores for In Situ Inductive Regeneration of Full Thickness Cartilage Defects 下载免费PDF全文
Yuankun Dai Zhenzhen Gao Lie Ma Dongan Wang Changyou Gao 《Macromolecular bioscience》2016,16(11):1632-1642
A bioactive scaffold with desired microstructure is of great importance to induce infiltration of somatic and stem cells, and thereby to achieve the in situ inductive tissue regeneration. In this study, a scaffold with oriented pores in the radial direction is prepared by using methacrylated hyaluronic acid (HA‐MA) via controlled directional cooling of a HA‐MA solution, and followed with photo‐crosslinking to stabilize the structure. Poly(lactide‐co‐glycolide) (PLGA) is further infiltrated to enhance the mechanical strength, resulting in a compressive modulus of 120 kPa. In vitro culture of bone marrow stem cells (BMSCs) reveals spontaneous cell aggregation inside this type of scaffold with a spherical morphology. In vivo transplantation of the cell‐free scaffold in rabbit knees for 12 w regenerates simultaneously both cartilage and subchondral bone with a Wakitani score of 2.8. Moreover, the expression of inflammatory factor interleukin‐1β (IL‐1β) is down regulated, although tumor necrosis factor‐α (TNF‐α) is remarkably up regulated. With the anti‐inflammatory, bioactive properties and good restoration of full thickness cartilage defect in vivo, the oriented macroporous HA‐MA/PLGA hybrid scaffold has a great potential for the practical application in the in situ cartilage regeneration.
20.
Near Infrared Dye Conjugated Nanogels for Combined Photodynamic and Photothermal Therapies 下载免费PDF全文
Mazdak Asadian‐Birjand Julian Bergueiro Stefanie Wedepohl Marcelo Calderón 《Macromolecular bioscience》2016,16(10):1432-1441
There is a need for new and smart formulations that will help overcome the limitations of organic dyes used in photodynamic (PDT) and photothermal (PTT) therapy and significantly accelerate their clinical translation. Therefore the aim of this work was to create a responsive nanogel scaffold as a smart vehicle for dye administration. We developed a methodology that enables the conjugation of organic dyes to thermoresponsive nanogels and yields biocompatible, nanometer‐sized products with low polydispersity. The potential of the dye‐nanogel conjugate as a photothermal and photodynamic agent has been demonstrated by an in vitro evaluation with a model human carcinoma cell line. Additionally, confocal cell images showed their cellular uptake profile and their potential for bioimaging and intracellular drug delivery. These conjugates are a promising scaffold as a theranostic agents and will enable further applications in combination with controlled drug release.