共查询到20条相似文献,搜索用时 62 毫秒
1.
Gangfeng Hu Luwei Xiao Hong Fu Dawei Bi Haitao Ma Peijian Tong 《Journal of materials science. Materials in medicine》2010,21(2):627-634
Injectable calcium sulphate/phosphate cement (CSPC) with degradable characteristic was developed by introduction of calcium
sulphate (CS) into calcium phosphate cement (CPC). The setting time, compressive strength, composition, degradation, cells
and tissue responses to the CSPC were investigated. The results show that the injectable CSPC with optimum L/P ratio exhibited
good injectability, and had suitable setting time and mechanical properties. Furthermore, the CSPC had good degradability
and its degradation significantly faster than that of CPC in Tris–HCl solution. Cell culture results indicate that CSPC was
biocompatible and could support MG63 cell attachment and proliferation. To investigate the in vivo biocompatibility and osteogenesis,
the CSPC were implanted in the bone defects of rabbits. Histological evaluation shows that the introduction of CS into CPC
enhanced the efficiency of new bone formation, and CSPC exhibited good biocompatibility, degradability and osteoconductivity
with host bone in vivo. It can be concluded that the injectable CSPC had a significant clinical advantage over CPC, and might
have potential to be applied in orthopedic, reconstructive and maxillofacial surgery, especially for minimally invasive techniques. 相似文献
2.
An injectable thermo-sensitive double crosslinking hydrogel based on thiolated chitosan (CS-TGA)/beta-glycerophosphate (β-GP)
was prepared by combining physical and chemical crosslinking. The effect of the concentrations of CS-TGA and β-GP on gelation
temperature of CS-TGA-GP hydrogel was investigated. The gelation and mechanical properties of CS-TGA-GP in situ gel system
were studied by oscillatory rheology and unconfined compression testing. By the physical interaction of CS-TGA and β-GP, CS-TGA-GP
system undergoes a fast gelation at body temperature within 2 min. In addition, CS-TGA-GP hydrogel contains a low concentration
of β-GP, which significantly decreases the toxicity of the gel. Owing to the chemical crosslinking of disulfide bonds, the
gel is durable and possesses high-mechanical strength without introducing any potential cytotoxicity. The integrity of CS-TGA-GP
hydrogel maintains for more than 30 days both in vitro and in vivo, and the interior morphology visualized by scanning electron
microscopy reveals that the gel has interconnected porous network structure. In vitro release behavior of protein from CS-TGA-GP
hydrogel was investigated using BSA as model protein. There is a sustained protein release from the gel without any initial
burst. In vitro cytotoxicity, hemolysis, and histopathological analysis reveal that the gel is biocompatible. These features
indicate that CS-TGA-GP hydrogel is a promising candidate for injectable protein delivery system and biomedical applications. 相似文献
3.
Studies on the gelation behaviors of the reactive blends of nylon1212 and functional elastomer were carried out. The results
show that the curves of the storage modulus(G′)–frequency (ω) exhibit a gel plateau in the low ω region, and the transition from liquid-like to solid-like viscoelastic
behaviors emerges with the concentration of SEBS-g-MA increasing. There exist the gelation behaviors in the blending process
similar to those of crosslinking polymer. Based on Winter’s method, the gel point of blends is determined to be, φg = 17.45 wt%, and the corresponding value of tanδ is 1.44. The gel index n calculated is 0.61 and the gel strength S
g is 1.08 × 104 Pa s0.61. However, the non-reactive blends of nylon1212 and elastomer have no emergence of gelation behaviors. The morphology analysis
shows that the gel point for the reactive blends is a threshold of cocontinuous morphology, and morphology analysis can also
be a method to determine the gel point. 相似文献
4.
O. M. Clarkin D. Boyd S. Madigan M. R. Towler 《Journal of materials science. Materials in medicine》2009,20(7):1563-1570
Glass polyalkenoate cements based on strontium calcium zinc silicate glasses (Zn-GPCs) and high molecular weight polyacrylic
acids (PAA) (MW; 52,000–210,000) have been shown to exhibit mechanical properties and in vitro bioactivity suitable for arthroplasty
applications. Unfortunately, these formulations exhibit working times and setting times which are too short for invasive surgical
applications such as bone void filling and fracture fixation. In this study, Zn-GPCs were formulated using a low molecular
weight PAA (MW; 12,700) and a modifying agent, trisodium citrate dihydrate (TSC), with the aim of improving the rheological
properties of Zn-GPCs. These novel formulations were then compared with commercial self-setting calcium phosphate cement,
Hydroset™, in terms of compressive strength, biaxial flexural strength and Young’s modulus, as well as working time, setting
time and injectability. The novel Zn-GPC formulations performed well, with prolonged mechanical strength (39 MPa, compression)
greater than both vertebral bone (18.4 MPa) and the commercial control (14 MPa). However, working times (2 min) and rheological
properties of Zn-GPCs, though improved, require further modifications prior to their use in minimally invasive surgical techniques. 相似文献
5.
Ho-Yeon Song A. H. M. Esfakur Rahman Byong-Taek Lee 《Journal of materials science. Materials in medicine》2009,20(4):935-941
In this study, an injectable bone substitute (IBS) consisting of citric acid, chitosan solution as the liquid phase and tetra
calcium phosphate (TTCP), dicalcium phosphate anhydrous (DCPA) and calcium sulfate hemihydrate (CSH) powders as the solid
phase was prepared. Four groups containing different percentages (0–30%) of calcium sulfate hemihydrate (CSH, CaSO4 · 0.5H2O) were investigated. Initial setting times for IBS with CSH were longer than those without CSH. The setting times for all
compositions were in the range of 25–45 min. The injectability was improved by the addition of CSH in the present system. Scanning electron
microscopy images showed that fiber-like crystallization appeared in the cements. The enhancement of crystallinity was confirmed
by XRD profiles where the peak intensity of HAp increased with incubation time and the addition of CSH. Also, the compressive
strength increased with the addition of CSH. The maximum compressive strength obtained for IBS was with 20% CSH after 28-day
incubation in 100% humidity at 37°C. 相似文献
6.
Lu Fan Yanru Ren Claus Burkhardt Ole Jung Reinhard Schnettler Mike Barbeck Xin Xiong 《Advanced Engineering Materials》2023,25(19):2300508
Bone tissue engineering has emerged as a promising approach to regenerate bone tissue, and injectable biomaterials have shown potential for bone regeneration applications due to their ease of administration and ability to fill irregularly shaped defects. This study aims to develop and characterize an injectable composite material comprising biphasic bone substitutes (BBS) and crosslinked porcine collagen type I for bone regeneration applications. The collagen is crosslinked via a UVA-riboflavin crosslinking strategy and evaluated by testing the physicochemical properties, including the rheological behavior, dynamic storage modulus (G′) and loss modulus (G″), and in vitro degradation process. The results show that the crosslinked collagen (xCol) exhibits suitable physicochemical properties for injectability and improved viscoelasticity and degradation resistance. Furthermore, xCol is then combined with BBS in a predetermined ratio, obtaining the injectable composite material. The biocompatibility of the materials is evaluated in vitro by XTT and BrdU assays on fibroblasts and preosteoblasts. The results demonstrate that the composite material is biocompatible and supporting pre-osteoblasts proliferation. In conclusion, the injectable composite material BBS-xCol has promising physiochemical and biological properties for bone regeneration applications. Further studies are warranted to evaluate its efficacy in vivo and optimize its composition for clinical translation. 相似文献
7.
Gladius Lewis Mark R. Towler Daniel Boyd Matthew J. German Anthony W. Wren Owen M. Clarkin Andrew Yates 《Journal of materials science. Materials in medicine》2010,21(1):59-66
Vertebroplasty (VP) and balloon kyphoplasty (BKP) are now widely used for treating patients in whom the pain due to vertebral
compression fractures is severe and has proved to be refractory to conservative treatment. These procedures involve percutaneous
delivery of a bolus of an injectable bone cement either directly to the fractured vertebral body, VB (VP) or to a void created
in it by an inflatable bone tamp (BKP). Thus, the cement is a vital component of both procedures. In the vast majority of
VPs and BKPs, a poly(methyl methacrylate) (PMMA) bone cement is used. This material has many shortcomings, notably lack of
bioactivity and very limited resorbability. Thus, there is room for alternative cements. We report here on two variants of
a novel, bioactive, Al-free, Zn-based glass polyalkenoate cement (Zn-GPC), and how their properties compare to those of an
injectable PMMA bone cement (SIMPL) that is widely used in VP and BKP. The properties determined were injectability, radiopacity,
uniaxial compressive strength, and biaxial flexural modulus. In addition, we compared the compression fatigue lives of a validated
synthetic osteoporotic VB model (a polyurethane foam cube with an 8 mm-diameter through-thickness cylindrical hole), at 0–2300 N
and 3 Hz, when the hole was filled with each of the three cements. A critical review of the results suggests that the performance
of each of the Zn-GPCs is comparable to that of SIMPL; thus, the former cements merit further study with a view to being alternatives
to an injectable PMMA cement for use in VP and BKP. 相似文献
8.
Injectable thermosensitive hydrogel based on chitosan and quaternized chitosan and the biomedical properties 总被引:1,自引:0,他引:1
Qiu Xia Ji Xi Guang Chen Qing Sheng Zhao Cheng Sheng Liu Xiao Jie Cheng Ling Chong Wang 《Journal of materials science. Materials in medicine》2009,20(8):1603-1610
A novel injectable thermosensitive hydrogel (CS–HTCC/α β-GP) was successfully designed and prepared using chitosan (CS), quaternized
chitosan (HTCC) and α,β-glycerophosphate (α,β-GP) without any additional chemical stimulus. The gelation point of CS–HTCC/α
β-GP can be set at a temperature close to normal body temperature or other temperature above 25°C. The transition process
can be controlled by adjusting the weight ratio of CS to HTCC, or different final concentration of α,β-GP. The optimum formulation
is (CS + HTCC) (2% w/v), CS/HTCC (5/1 w/w) and α,β-GP 8.33% or 9.09% (w/v), where the sol–gel transition time was 3 min at
37°C. The drug released over 3 h from the CS–HTCC/α,β-GP thermosensitive hydrogel in artificial saliva pH 6.8. In addition,
CS–HTCC/α,β-GP thermosensitive hydrogel exhibited stronger antibacterial activity towards two periodontal pathogens (Porphyromonas gingivalis, P.g and Prevotella intermedia, P.i). CS–HTCC/α, β-GP thermosensitive hydrogel was a considerable candidate as a local drug delivery system for periodontal treatment. 相似文献
9.
Zhu XS Zhang ZM Mao HQ Geng DC Zou J Wang GL Zhang ZG Wang JH Chen L Yang HL 《Journal of materials science. Materials in medicine》2011,22(1):159-164
New injectable bone substitutes have been developed that are, unlike polymethylmethacrylate, biologically active and have
an osteogenic effect leading to osteogenesis and bone remodeling for vertebroplasty or kyphoplasty. In this study, we developed
a sheep vertebral bone defect model to evaluate the new bioactive materials and assessed the feasibility of the model in vivo.
Bone voids were experimentally created on lumbar vertebrae L2–L5 with L1 and L6 left intact as a normal control in mature
sheep. The defect vertebrae L2–L5 in each sheep were randomized to receive augmentation with calcium phosphate cement (CPC)
or sham. Vertebrae (L1–L6) were collected after 2 and 24 weeks of the cement augmentation and their strength and stiffness,
as well as osseointegration activity and biodegradability, were evaluated. Finally, CPC significantly improved the strength
and stiffness of vertebrae but did not yet restore it to the normal level at 24 weeks. Osteogenesis occurred at a substantially
high level after 24 weeks of CPC augmentation or sham. Therefore, the sheep vertebral model with one void, 6.0 mm in diameter
and 15.0 mm in depth, is replicable and can be used for evaluating the new injectable bioactive materials in vertebral augmentation
or reconstruction. 相似文献
10.
S. Pina P. M. C. Torres J. M. F. Ferreira 《Journal of materials science. Materials in medicine》2010,21(2):431-438
The influence of magnesium- and strontium-substitutions on injectability and mechanical performance of brushite-forming α-TCP
cements has been evaluated in the present work. The effects of Mg- and Sr-substitutions on crystalline phase composition and
lattice parameters were determined through quantitative X-ray phase analysis and structural Rietveld refinement of the starting
calcium phosphate powders and of the hardened cements. A noticeable dependence of injectability on the liquid-to-powder ratio
(LPR), smooth plots of extrusion force versus syringe plunger displacement and the absence of filter pressing effects were
observed. For LPR values up to 0.36 ml g−1, the percentage of injectability was always higher and lower for Mg-containing cements and for Sr-containing cements, respectively,
while all the pastes could be fully injected for LPR > 0.36 ml g−1. The hardened cements exhibited relatively high wet compressive strength values (~17–25 MPa) being the Sr- and Mg-containing
cements the strongest and the weakest, respectively, holding an interesting promise for uses in trauma surgery such as for
filling bone defects and in minimally invasive techniques such as percutaneous vertebroplasty to fill lesions and strengthen
the osteoporotic bone. 相似文献
11.
Rath SN Pryymachuk G Bleiziffer OA Lam CX Arkudas A Ho ST Beier JP Horch RE Hutmacher DW Kneser U 《Journal of materials science. Materials in medicine》2011,22(5):1279-1291
Smart matrices are required in bone tissue-engineered grafts that provide an optimal environment for cells and retain osteo-inductive
factors for sustained biological activity. We hypothesized that a slow-degrading heparin-incorporated hyaluronan (HA) hydrogel
can preserve BMP-2; while an arterio–venous (A–V) loop can support axial vascularization to provide nutrition for a bio-artificial
bone graft. HA was evaluated for osteoblast growth and BMP-2 release. Porous PLDLLA–TCP–PCL scaffolds were produced by rapid
prototyping technology and applied in vivo along with HA-hydrogel, loaded with either primary osteoblasts or BMP-2. A microsurgically
created A–V loop was placed around the scaffold, encased in an isolation chamber in Lewis rats. HA-hydrogel supported growth
of osteoblasts over 8 weeks and allowed sustained release of BMP-2 over 35 days. The A–V loop provided an angiogenic stimulus
with the formation of vascularized tissue in the scaffolds. Bone-specific genes were detected by real time RT-PCR after 8 weeks.
However, no significant amount of bone was observed histologically. The heterotopic isolation chamber in combination with
absent biomechanical stimulation might explain the insufficient bone formation despite adequate expression of bone-related
genes. Optimization of the interplay of osteogenic cells and osteo-inductive factors might eventually generate sufficient
amounts of axially vascularized bone grafts for reconstructive surgery. 相似文献
12.
Zhang XG Teng DY Wu ZM Wang X Wang Z Yu DM Li CX 《Journal of materials science. Materials in medicine》2008,19(12):3525-3533
The development of injectable nanoparticulate “stealth” carriers for protein delivery is a major challenge. The objective
of this work was to investigate the possibility of achieving the controlled release of a model protein, insulin, from PEG-grafted
chitosan (PEG-g-chitosan) nanoparticles (mean diameter 150–300 nm) prepared by the ion gelation method. Insulin was efficiently incorporated
into the nanoparticles, and reached as high as 38%. In vitro release showed that it could control the insulin release by choosing
the composition, loading and release temperature. We observed that the composition of the nanoparticle surface (C/O ratio)
increased from 2.40 to 3.23, with an increase in the incubation time. Therefore, we concluded that during this time, insulin
release from PEG-g-chitosan nanoparticles followed a diffusion mechanism in which erosion was negligible. The experiments also demonstrated
that PEG-g-chitosan helped to maintain the natural structure of the protein entrapped in the nanoparticles. 相似文献
13.
Hong-Liang Wei Kai Yao Hui-Juan Chu Zhi-Cheng Li Jing Zhu Yan-Min Shen Zi-Xuan Zhao Ya-Li Feng 《Journal of Materials Science》2012,47(1):332-340
Novel intelligent hydrogels containing β-cyclodextrins were prepared by tandem physical and chemical crosslinking method based
on Diels–Alder reaction. First, dienophile-functionalized cyclodextrins (HCD–AMI) were synthesized by the coupling reaction
of hydroxyethyl-β-cyclodextrins and N-maleoyl alanine (AMI); diene-functionalized polymers (PFMIPA) were synthesized by free radical copolymerization of N-isopropylacrylamide and furfuryl amine maleic acid monoamide, a novel monomer synthesized in our lab. Then, the LCSTs of
the PFMIPA were estimated by transmittance measurements of copolymer solutions. After the as-synthesized PFMIPA and HCD–AMI
were dissolved separately in water and mixed, the hydrogels with physical crosslinks formed quickly within 10 s at 37 °C.
Subsequently, chemical crosslinks came into being gradually due to Diels–Alder reaction. Therefore, there are both physical
crosslinks and chemical crosslinks in as-prepared hydrogels, resulting in the improvement of the mechanical strength of the
hydrogels. And the in vitro degradation behaviors of the resultant hydrogels were given a pilot study. A general gravimetric
method was used to study the swelling behavior of the hydrogels. It was found that the hydrogels showed good pH/temperature-sensitivity.
The strategy described here has several advantages for preparing intelligent hydrogels including tunable gelation rate, mild
reaction conditions, no initiator or catalyzer, and no organic solvent. We believe that this novel, potentially biocompatible
hydrogels could have biomedical applications, especially in the area of tissue engineering and drug-controlled release carriers. 相似文献
14.
Saeed Hesaraki Masoud Alizadeh Hamid Nazarian Davood Sharifi 《Journal of materials science. Materials in medicine》2010,21(2):695-705
Strontium is known to reduce bone resorption and stimulate bone formation. Incorporation of strontium into calcium phosphate
bioceramics has been widely reported. In this work, calcium and calcium/strontium silicophosphate glasses were synthesized
from the sol–gel process and their rheological, thermal, and in vitro biological properties were studied and compared to each
other. The results showed that the gel viscosity and thus the rate of gel formation increased by using strontium in glass
composition and by increasing aging temperature. In strontium-containing glass, the crystallization temperature increased
and the type of the crystallized phase was different to that of strontium-free glass. Both glasses favored precipitation of
calcium phosphate layer when they were soaked in simulated body fluid; however strontium seemed to retard the rate of precipitation
slightly. The in vitro biodegradation rate of the strontium/calcium silicophosphate glass was higher than that of strontium-free
one. The cell culture experiments carried out using rat calvaria osteoblasts showed that the incorporation of strontium into
the glass composition stimulated proliferation of the cells and enhanced their alkaline phosphatase activity, depending on
cell culture period. 相似文献
15.
H. Buscail C. T. Nguyen R. Cueff C. Issartel F. Riffard S. Perrier 《Journal of Materials Science》2009,44(15):3968-3974
The effect of lanthanum sol–gel coatings was studied in order to improve the alumina scale adherence during the model Fe–20Cr–5Al
alloy oxidation, at 1100 °C, in air. Various sol–gel coating procedures were applied. Argon annealing of the lanthanum sol–gel
coating was tested at temperatures ranging between 600 and 1000 °C. The coating crystallographic nature was characterized
by X-ray diffraction (XRD) depending on the annealing temperature. The oxidation process has been examined at 1100 °C by in situ
XRD on blank Fe–20Cr–5Al, sol–gel coated and argon-annealed specimens. This study shows that the coating argon annealing at
1000 °C leads to the preferential formation of LaAlO3 instead of La2O3. This coating procedure leads to an alumina scale formation showing the best adherence under thermal cycling conditions at
1100 °C. 相似文献
16.
Hyun Mee Lee Yeon-Hee Yoon Woo-Back Lee Jong-Ki Kim 《Journal of materials science. Materials in medicine》2009,20(9):1917-1926
To prepare a gel-forming poly-l-guluronic acid (Poly-G) from no guluronate-rich Laminaria japonica, a new hydrolysis method was employed with a lower HCl concentration (0.025–0.15 M) and a shorter treatment time (5 min).
The Poly-Gs were set to measure purity, presence of poly-l-guluronic block, molecular weight distribution, polymer yield, viscosity, and compressive gel strength. Finally, the Poly-G
was tested to embolize the renal vascular system by using a rabbit model and angiography. Optimized Poly-G could be selected
with respect to wt% concentration, polymer yield, gel-forming stability, viscosity, and gel strength as an endovascular embolizing
agent. Overall, 0.4–0.6% of 0.03 M-Poly-G obtained from acid treatment with 0.03 M of HCl had molecular weights greater than
80 kDa, and the best gelling capacity with an injectable viscosity (30–120 cP). It was successfully delivered into the vascular
bed of a rabbit kidney and was shown angiographically to embolize the renal vascular system. 相似文献
17.
To investigate the effect of injectable PLGA sphere’s diameter on adipose tissue engineering, rabbit mesenchymal stem cells
were attached to various diameters of injectable PLGA spheres (<75; 75–100; 100–150; 150–200; and 200–250 μm). These five
groups were cultured in adipogenic media for 2 weeks in vitro and injected into necks of nude mice. Prior to in vivo study,
cell proliferation and adipogenic differentiation were determined by hexosaminidase assay and Oil red O staining after 2 weeks.
Group C (100–150 μm) showed the highest adipogenic differentiation and the proliferation capacity of Group B (75–100 μm) was
significantly higher than that of any other group. We harvested newly formed tissues from necks of nude mice after 1 and 4 weeks.
Although PLGA spheres have not been degraded and there was no significant histological difference among various sizes of spheres
after 1 week, well-organized fat pads (PLGA spheres were completely degraded) could be observed, and the histology of the
100–150 μm groups resembled that of native tissue after 4 weeks. Based on these experiments, we could conclude that the optimal
size of PLGA spheres for adipogenesis was 100–150 μm. 相似文献
18.
Yan Sheng Yuan Yuan Changsheng Liu Xinyi Tao Xiaoqian Shan Feng Xu 《Journal of materials science. Materials in medicine》2009,20(9):1881-1891
The aim of the present work is to investigate the effect of PEG content in copolymer on physicochemical properties, in vitro
macrophage uptake, in vivo pharmacokinetics and biodistribution of poly(lactic acid) (PLA)–poly(ethylene glycol) (PEG) hemoglobin
(Hb)-loaded nanoparticles (HbP) used as blood substitutes. The HbP were prepared from PLA and PLA–PEG copolymer of varying
PEG contents (5, 10, and 20 wt%) by a modified w/o/w method and characterized with regard to their morphology, size, surface
charge, drug loading, surface hydrophilicity, and PEG coating efficiency. The in vitro macrophage uptake, in vivo pharmacokinetics,
and biodistribution following intravenous administration in mice of HbP labeled with 6-coumarin, were evaluated. The HbP prepared
were all in the range of 100–200 nm with highest encapsulation efficiency 87.89%, surface charge −10 to −33 mV, static contact
angle from 54.25° to 68.27°, and PEG coating efficiency higher than 80%. Compared with PLA HbP, PEGylation could notably avoid
the macrophage uptake of HbP, in particular when the PEG content was 10 wt%, a minimum uptake (6.76%) was achieved after 1 h
cultivation. In vivo, besides plasma, the major cumulative organ was the liver. All PLA–PEG HbP exhibited dramatically prolonged
blood circulation and reduced liver accumulation, compared with the corresponding PLA HbP. The PEG content in copolymer affected
significantly the survival time in blood. Optimum PEG coating (10 wt%) appeared to exist leading to the most prolonged blood
circulation of PLA–PEG HbP, with a half-life of 34.3 h, much longer than that obtained by others (24.2 h). These results demonstrated
that PEG 10 wt% modified PLA HbP with suitable size, surface charge, and surface hydrophilicity, has a promising potential
as long-circulating oxygen carriers with desirable biocompatibility and biofunctionality. 相似文献
19.
Jasmina Stojkovska Branko Bugarski Bojana Obradovic 《Journal of materials science. Materials in medicine》2010,21(10):2869-2879
Alginate hydrogels in forms of discs and packed beds of microbeads (~800 μm) were tested in a novel bioreactor at 10% strain
using two regimes: at a loading rate of 337.5 μm/s and at sequential increments of 50 μm displacement every 30 min. Compressive
strength increased with the increase in alginate concentration (1.5 vs. 2% w/w) and the content of guluronic residues (38.5
vs. 67%). Packed beds of microbeads exhibited significantly higher (~1.5–3.4 fold) compression moduli than the respective
discs indicating the effects of gel form and entrapped water. Short-term cultivation of microbeads with immobilized bovine
calf chondrocytes (1.5% w/w, 33 × 106 cells/ml) under biomimetic conditions (dynamic compression: 1 h on/1 h off, 0.42 Hz, 10% strain) resulted in cell proliferation
and bed compaction, so that the compression modulus slightly increased. Thus, the novel bioreactor demonstrated advantages
in evaluation of biomaterial properties and cell-biomaterial interactions under in vivo–like settings. 相似文献
20.
Danial Barati Kira Watkins Zhibin Wang Fan Yang 《Small (Weinheim an der Bergstrasse, Germany)》2020,16(22)
Poly(lactide‐co‐glycolide) (PLGA) has been widely used as a tissue engineering scaffold. However, conventional PLGA scaffolds are not injectable, and do not support direct cell encapsulation, leading to poor cell distribution in 3D. Here, a method for fabricating injectable and intercrosslinkable PLGA microribbon‐based macroporous scaffolds as 3D stem cell niche is reported. PLGA is first fabricated into microribbon‐shape building blocks with tunable width using microcontact printing, then coated with fibrinogen to enhance solubility and injectability using aqueous solution. Upon mixing with thrombin, firbornogen‐coated PLGA microribbons can intercrosslink into 3D scaffolds. When subject to cyclic compression, PLGA microribbon scaffolds exhibit great shock‐absorbing capacity and return to their original shape, while conventional PLGA scaffolds exhibit permanent deformation after one cycle. Using human mesenchymal stem cells (hMSCs) as a model cell type, it is demonstrated that PLGA μRB scaffolds support homogeneous cell encapsulation, and robust cell spreading and proliferation in 3D. After 28 days of culture in osteogenic medium, hMSC‐seeded PLGA μRB scaffolds exhibit an increase in compressive modulus and robust bone formation as shown by staining of alkaline phosphatase, mineralization, and collagen. Together, the results validate PLGA μRBs as a promising injectable, macroporous, non‐hydrogel‐based scaffold for cell delivery and tissue regeneration applications. 相似文献