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1.
Skeletal Radiol ; 51(9): 1853-1863, 2022 Sep.
Article in English | MEDLINE | ID: mdl-35347404

ABSTRACT

OBJECTIVE: To evaluate the performance and reliability of the single-energy metal artifact reduction (SEMAR) algorithm in patients with different orthopedic hardware at the hips. MATERIALS AND METHODS: A total of 153 patients with hip instrumentation who had undergone CT with adaptive iterative dose reduction (AIDR) 3D and SEMAR algorithms between February 2015 and October 2019 were included retrospectively. Patients were divided into 5 groups by the hardware type. Two readers with 21 and 13 years of experience blindly reviewed all image sets and graded the extent of artifacts and imaging quality using 5-point scales. To evaluate reliability, the mean densities and image noises were measured at the urinary bladder, veins, and fat in images with artifacts and the reference images. RESULTS: No significant differences were found in the mean densities of the urinary bladder, veins, and fat between the SEMAR images with artifacts (7.57 ± 9.49, 40.29 ± 23.07, 86.78 ± 38.34) and the reference images (7.77 ± 6.2, 40.27 ± 8.66, 89.10 ± 20.70) (P = .860, .994, .392). Image noises of the urinary bladder in the SEMAR images with artifacts (14.25 ± 4.50) and the SEMAR reference images (9.69 ± 1.29) were significantly higher than those in the AIDR 3D reference images (9.11 ± 1.12) (P < .001; P < .001). All AIDR 3D images were non-diagnostic (overall quality ≤ 3) and less than a quarter of the SEMAR images were non-diagnostic (16.7-23.7%), mainly in patients with prostheses [reader 1: 91.7% (22/24); reader 2: 92.6% (25/27)]. CONCLUSION: The SEMAR algorithm significantly reduces metal artifacts in CT images, more in patients with internal fixations than in patients with prostheses, and provides reliable attenuation of soft tissues.


Subject(s)
Artifacts , Image Processing, Computer-Assisted , Algorithms , Humans , Image Processing, Computer-Assisted/methods , Metals , Reproducibility of Results , Retrospective Studies , Tomography, X-Ray Computed/methods
2.
Radiol Case Rep ; 17(1): 212-215, 2022 Jan.
Article in English | MEDLINE | ID: mdl-34824652

ABSTRACT

Omental lymphangioma is a rare pathology presented in the abdomen, and it can mimic several clinical conditions. Owing to its variable signs and symptoms, making a correct diagnosis by clinicians may be difficult. Surgical excision is the gold standard treatment. In this article, we report a case who presented with nonspecific abdominal complaints, and underwent surgery. Final pathologic diagnosis revealed omental cystic lymphangioma.

3.
J Comput Assist Tomogr ; 44(6): 977-983, 2020.
Article in English | MEDLINE | ID: mdl-32976262

ABSTRACT

OBJECTIVE: To determine the frequencies of fat-water swaps in iterative decomposition of water and fat with echo asymmetry and least-squares estimation (IDEAL) water-only images of the postinstrumentation spine and discuss the efficiency of in-phase imaging in improving visibility of the thecal sac. MATERIALS AND METHODS: A total of 276 patients (167 women; mean age, 62.3 years; range, 23-89 years) with metallic devices on the lumbar spine who received complete routine 1.5 T MR imaging, including axial and sagittal images of T1-weighted, T2-weighted, and T2-weighted IDEAL sequences, were included. The exclusion criteria were significant motion artifacts and severe metallic artifacts in any one of the sequences. The images were reviewed by two radiologists to identify fat-water swaps that were divided into 3 groups: extraspinal swaps, intraspinal swaps in sagittal images, and intraspinal swaps in axial images. The qualitative evaluations for the spinal canal in axial images were performed by rating on a five-point scale. Side-by-side comparisons of T2-weighted images and IDEAL in-phase images were also performed. RESULTS: In patient-based data of 276 patients, extraspinal fat-water swaps were noted in 10 patients (3.6%) and intraspinal swaps were noted in 160 patients (58.0%). The intraspinal swaps had a higher incidence in the patients with more levels of metallic devices with screws and the trend was not noted in the extraspinal swaps. A total of 928 axial levels were evaluated in the level-based data of axial images. T1-weighted, T2-weighted, and IDEAL in-phase images had significantly better imaging quality than the IDEAL water-only images (3.9 ± 0.4, 3.9 ± 0.3, 3.8 ± 0.4 vs 3.0 ± 1.3, all P < 0.001). Compared with T2-weighted images, most of the IDEAL in-phase images (reader 1, 90.9%; reader 2, 86.7%) present similar quality. CONCLUSION: Iterative decomposition of water and fat with echo asymmetry and least-squares estimation sequence can provide good fat suppression in most spine MRI with metallic devices but the loss of cerebrospinal fluid signal intensities due to fat-water swaps are noted in more than half of postinstrumentation spine. Routine reconstruction of in-phase images is recommended to improve evaluation of the thecal sac by avoiding pitfall caused by fat-water swaps.


Subject(s)
Adipose Tissue/diagnostic imaging , Artifacts , Image Processing, Computer-Assisted/methods , Internal Fixators , Magnetic Resonance Imaging/methods , Adult , Aged , Aged, 80 and over , Female , Humans , Least-Squares Analysis , Lumbar Vertebrae/diagnostic imaging , Male , Metals , Middle Aged , Retrospective Studies , Signal-To-Noise Ratio , Spine/diagnostic imaging , Water , Young Adult
4.
Transplant Proc ; 52(9): 2778-2780, 2020 Nov.
Article in English | MEDLINE | ID: mdl-32434746

ABSTRACT

A bronchobiliary fistula (BBF), which is defined by abnormal communication between the biliary system and the bronchial tree, is usually regarded as a consequence of local infection, such as hydatid or amebic disease of the liver, hepatic abscess, trauma, neoplasm, and other causes of biliary obstruction. We present a 40-year-old female patient who received a living donor liver transplantation for autoimmune hepatitis and who suffered from biliary stricture at the anastomosis, bile leakage in the right subphrenic region, and development of a BBF 1 year later. Magnetic resonance cholangiography (MRC) and fistulography showed a fistula between the subphrenic biloma and right lower bronchus. The patient was treated successfully by the subphrenic drainage tube and percutaneous transhepatic cholangial drainage (PTCD) crossing the biliary stricture. In conclusion, the BBF is an extremely rare complication after liver transplantation; and minimal-invasive procedures, such as percutaneous drainage and PTCD, are useful for the closure of BBF. This case report is approved by the Institutional Review Board (IRB) of Kaohsiung Medical University Chung-Ho Memorial Hospital, certifying that no prisoners were used in the case and that participants were neither paid nor coerced.


Subject(s)
Biliary Fistula/etiology , Biliary Fistula/surgery , Bronchial Fistula/etiology , Bronchial Fistula/surgery , Liver Transplantation/adverse effects , Adult , Biliary Fistula/diagnostic imaging , Bronchial Fistula/diagnostic imaging , Cholangiography/methods , Drainage/methods , Female , Humans , Living Donors , Postoperative Complications/surgery
5.
Int Wound J ; 17(2): 394-404, 2020 Apr.
Article in English | MEDLINE | ID: mdl-31845534

ABSTRACT

The use of haemostatic agents can provide life-saving treatment for patients who suffer from massive bleeding in both prehospital and intraoperative conditions. However, there are still urgent demands for novel haemostatic materials that exhibit better haemostatic activity, biocompatibility, and biodegradability than existing products. In the present study, we aim to evaluate the feasibility of new wound dressing, RapidClot, for treating uncontrolled haemorrhage through a series of in vitro assessments to determine the swelling ratio, clotting time, enzymatic degradation, haemolytic activity, cytotoxicity, cell proliferation, and migration. The results indicated that the RapidClot revealed better water adsorption capacity and shorter blood clotting time (132.7 seconds) than two commercially available haemostatic agents Celox (378.7 seconds) and WoundSeal (705.3 seconds). Additionally, the RapidClot dressing exhibited a similar level of degradability in the presence of hyaluronidase and lysozyme as that of Celox, whereas negligible degradation of WoundSeal was obtained. Although both Celox and RapidClot revealed a similar level in cell viability (above than 90%) against NIH/3 T3 fibroblasts, improved cell proliferation and migration could be obtained in RapidClot. Taking together, our results demonstrated that RapidClot could possess a great potential for serving as an efficient healing dressing with haemorrhage control ability.


Subject(s)
Alginates/therapeutic use , Hemorrhage/therapy , Hemostasis/drug effects , Hyaluronic Acid/therapeutic use , Powders/therapeutic use , Wound Healing/drug effects , Wounds and Injuries/drug therapy , In Vitro Techniques
6.
Biomaterials ; 35(1): 174-84, 2014 Jan.
Article in English | MEDLINE | ID: mdl-24120047

ABSTRACT

Cell sheet technology has been widely employed for the treatment of myocardial infarction (MI), but cell sheet fabrication generally requires the use of thermo-responsive dishes. Here we developed a method for the preparation of adipose-derived stem cell (ASC) sheet that obviated the need of thermo-responsive dishes. This method only required the seeding of rabbit ASC onto 6-well plates at an appropriate cell density and culture in appropriate medium, and the cells were able to develop into ASC sheet in 2 days. The ASC sheet allowed for transduction with the hybrid baculovirus at efficiencies >97%, conferring robust and prolonged (>35 days) overexpression of vascular endothelial growth factor (VEGF). The ASC sheet was easily detached by brief (10 s) trypsinization and saline wash, while retaining the extracellular matrix and desired physical properties. The ASC sheet formation and VEGF expression promoted cell survival under hypoxia in vitro. Epicardial implantation of the VEGF-expressing ASC sheet to rabbit MI models reduced the infarct size and improved cardiac functions to non-diseased levels, as judged from the left ventrical ejection fraction/myocardial perfusion. The VEGF-expressing ASC sheet also effectively prevented myocardial wall thinning, suppressed myocardium fibrosis and enhanced blood vessel formation. These data implicated the potential of this method for the preparation of genetically engineered ASC sheet and future MI treatment.


Subject(s)
Adipose Tissue/cytology , Baculoviridae/genetics , Myocardial Infarction/therapy , Stem Cells/cytology , Vascular Endothelial Growth Factor A/genetics , Animals , Magnetic Resonance Imaging , Male , Rabbits , Stem Cell Transplantation , Tissue Engineering
7.
Mol Ther ; 22(1): 186-95, 2014 Jan.
Article in English | MEDLINE | ID: mdl-23851345

ABSTRACT

Adipose-derived stem cells (ASCs) hold promise for cartilage regeneration but their chondrogenesis potential is inferior. Here, we used a baculovirus (BV) system that exploited FLPo/Frt-mediated transgene recombination and episomal minicircle formation to genetically engineer rabbit ASCs (rASCs). The BV system conferred prolonged and robust TGF-ß3/BMP-6 expression in rASCs cultured in porous scaffolds, which critically augmented rASCs chondrogenesis and suppressed osteogenesis/hypertrophy, leading to the formation of cartilaginous constructs with improved maturity and mechanical properties in 2-week culture. Twelve weeks after implantation into full-thickness articular cartilage defects in rabbits, these engineered constructs regenerated neocartilages that resembled native hyaline cartilages in cell morphology, matrix composition and mechanical properties. The neocartilages also displayed cartilage-specific zonal structures without signs of hypertrophy and degeneration, and eventually integrated with host cartilages. In contrast, rASCs that transiently expressed TGF-ß3/BMP-6 underwent osteogenesis/hypertrophy and resulted in the formation of inferior cartilaginous constructs, which after implantation regenerated fibrocartilages. These data underscored the crucial role of TGF-ß3/BMP-6 expression level and duration in rASCs in the cell differentiation, constructs properties and in vivo repair. The BV-engineered rASCs that persistently express TGF-ß3/BMP-6 improved the chondrogenesis, in vitro cartilaginous constructs production and in vivo hyaline cartilage regeneration, thus representing a remarkable advance in cartilage engineering.


Subject(s)
Adipose Tissue/cytology , Chondrogenesis , Guided Tissue Regeneration , Stem Cells/metabolism , Animals , Biomechanical Phenomena , Bone Morphogenetic Protein 6/genetics , Bone Morphogenetic Protein 6/metabolism , Cartilage/cytology , Cartilage/metabolism , Chondrogenesis/genetics , Gene Expression , Gene Order , Genetic Vectors/genetics , Male , Rabbits , Tissue Engineering , Tissue Scaffolds , Transduction, Genetic , Transforming Growth Factor beta3/genetics , Transforming Growth Factor beta3/metabolism
8.
Biomaterials ; 34(37): 9401-12, 2013 Dec.
Article in English | MEDLINE | ID: mdl-24016854

ABSTRACT

Calvarial bone healing is difficult and grafts comprising adipose-derived stem cells (ASCs) and PLGA (poly(lactic-co-glycolic acid)) scaffolds barely heal rabbit calvarial defects. Although calvarial bone forms via intramembranous ossification without cartilage templates, it was suggested that chondrocytes/cartilages promote calvarial healing, thus we hypothesized that inducing ASCs chondrogenesis and endochondral ossification involving cartilage formation can improve calvarial healing. To evaluate this hypothesis and selectively induce osteogenesis/chondrogenesis, rabbit ASCs were engineered to express the potent osteogenic (BMP2) or chondrogenic (TGF-ß3) factor, seeded into either apatite-coated PLGA or gelatin sponge scaffolds, and allotransplanted into critical-size calvarial defects. Among the 4 ASCs/scaffold constructs, gelatin constructs elicited in vitro chondrogenesis, in vivo osteogenic metabolism and calvarial healing more effectively than apatite-coated PLGA, regardless of BMP2 or TGF-ß3 expression. The BMP2-expressing ASCs/gelatin triggered better bone healing than TGF-ß3-expressing ASCs/gelatin, filling ≈ 86% of the defect area and ≈ 61% of the volume at week 12. The healing proceeded via endochondral ossification, instead of intramembranous pathway, as evidenced by the formation of cartilage that underwent osteogenesis and hypertrophy. These data demonstrated ossification pathway switching and significantly augmented calvarial healing by the BMP2-expressing ASCs/gelatin constructs, and underscored the importance of growth factor/scaffold combinations on the healing efficacy and pathway.


Subject(s)
Adipose Tissue/cytology , Bone Morphogenetic Protein 2/genetics , Skull/injuries , Stem Cells/cytology , Tissue Scaffolds/chemistry , Transforming Growth Factor beta3/genetics , Wound Healing , Adipose Tissue/metabolism , Animals , Bone Morphogenetic Protein 2/metabolism , Cell Engineering , Cells, Cultured , Chondrogenesis , Gelatin/chemistry , Gene Expression , Lactic Acid/chemistry , Osteogenesis , Polyglycolic Acid/chemistry , Polylactic Acid-Polyglycolic Acid Copolymer , Rabbits , Stem Cells/metabolism , Transforming Growth Factor beta3/metabolism
9.
Biotechnol Adv ; 31(8): 1695-706, 2013 Dec.
Article in English | MEDLINE | ID: mdl-23994567

ABSTRACT

Gene therapy has converged with bone engineering over the past decade, by which a variety of therapeutic genes have been delivered to stimulate bone repair. These genes can be administered via in vivo or ex vivo approach using either viral or nonviral vectors. This article reviews the fundamental aspects and recent progresses in the gene therapy-based bone engineering, with emphasis on the new genes, viral vectors and gene delivery approaches.


Subject(s)
Bone and Bones , Gene Transfer Techniques , Genetic Therapy , Regenerative Medicine , Tissue Engineering , Animals , Genetic Vectors , Humans , Mice , Viruses
10.
Nucleic Acids Res ; 41(14): e139, 2013 Aug.
Article in English | MEDLINE | ID: mdl-23716635

ABSTRACT

Baculovirus (BV) is a promising gene vector but mediates transient expression. To prolong the expression, we developed a binary system whereby the transgene in the substrate BV was excised by the recombinase (ΦC31o, Cre or FLPo) expressed by a second BV and recombined into smaller minicircle. The recombination efficiency was lower by ΦC31o (≈40-75%), but approached ≈90-95% by Cre and FLPo in various cell lines and stem cells [e.g. human adipose-derived stem cells (hASCs)]. Compared with FLPo, Cre exerted higher expression level and lower negative effects; thus, we incorporated additional cis-acting element [oriP/Epstein-Barr virus nuclear antigen 1 (EBNA1), scaffold/matrix attached region or human origin of replication (ori)] into the Cre-based BV system. In proliferating cells, only oriP/EBNA1 prolonged the transgene expression and maintained the episomal minicircles for 30 days without inadvertent integration, whereas BV genome was degraded in 10 days. When delivering bmp2 or vegf genes, the efficient recombination/minicircle formation prolonged and enhanced the growth factor expression in hASCs. The prolonged bone morphogenetic protein 2 expression ameliorated the osteogenesis of hASCs, a stem cell with poor osteogenesis potential. Altogether, this BV vector exploiting Cre-mediated recombination and oriP/EBNA1 conferred remarkably high recombination efficiency, which prolonged and enhanced the transgene expression in dividing and non-dividing cells, thereby broadening the applications of BV.


Subject(s)
Baculoviridae/genetics , Recombinases/metabolism , Transgenes , Adipose Tissue/cytology , Animals , Cell Line , Cell Survival , Cells, Cultured , Cricetinae , DNA, Circular/metabolism , Gene Expression , Genetic Vectors , Humans , Intercellular Signaling Peptides and Proteins/genetics , Intercellular Signaling Peptides and Proteins/metabolism , Matrix Attachment Regions , Osteogenesis , Rabbits , Recombination, Genetic , Replication Origin , Stem Cells/cytology , Stem Cells/metabolism
11.
J Virol ; 87(9): 4965-73, 2013 May.
Article in English | MEDLINE | ID: mdl-23408634

ABSTRACT

Baculovirus (BV) is a promising gene therapy vector and typically requires readministration because BV mediates transient expression. However, how the prime-boost regimen triggers BV-specific adaptive responses and their impacts on BV readministration, transgene expression, and therapeutic/vaccine efficacy remain unknown. Here we unraveled that BV injection into BALB/c mice induced the production of BV-specific antibodies, including IgG1 and IgG2a, which could neutralize BV by antagonizing the envelope protein gp64 and impede BV-mediated transgene expression. Moreover, humans did not possess preexisting anti-BV antibodies. BV injection also elicited BV-specific Th1 and Th2 responses as well as CD4(+) and CD8(+) T cell responses. gp64 was a primary immunogen to activate the antibody and CD8(+) T cell response, with its peptide at positions 457 to 465 (peptide 457-465) being the major histocompatibility complex (MHC) class I epitope to stimulate CD8(+) T cell and cytotoxic responses. Nonetheless, a hybrid Sleeping Beauty-based BV enabled long-term expression for >1 year by a single injection, indicating that the T cell responses did not completely eradicate BV-transduced cells and implicating the potential of this hybrid BV vector for gene therapy. These data unveil that BV injection triggers adaptive immunity and benefit rational design of BV administration schemes for gene therapy and vaccination.


Subject(s)
Adaptive Immunity , Baculoviridae/immunology , Genetic Vectors/immunology , Transgenes , Animals , Baculoviridae/genetics , CD8-Positive T-Lymphocytes/immunology , Cell Line , Female , Genetic Therapy , Genetic Vectors/genetics , Humans , Mice , Mice, Inbred BALB C , Th1 Cells/immunology , Th2 Cells/immunology
12.
Biomaterials ; 33(30): 7422-34, 2012 Oct.
Article in English | MEDLINE | ID: mdl-22796166

ABSTRACT

Baculovirus holds promise for genetic modification of adipose-derived stem cells (ASCs) and bone engineering. To explore the immune responses during bone healing and the cell fate, ASCs were mock-transduced (Mock group), transduced with the baculovirus transiently expressing growth factors promoting osteogenesis (BMP2) or angiogenesis (VEGF) (S group), or transduced with hybrid baculoviruses persistently expressing BMP2/VEGF (L group). After allotransplantation into massive femoral defects in rabbits, these 3 groups triggered similar degrees of transient inflammatory response (e.g. neutrophil proliferation and immune cell infiltration into the graft site), revealing that baculovirus and transgene products did not exacerbate the inflammation. The cells in all 3 groups underwent apoptosis initially, persisted for at least 4 weeks and were eradicated thereafter. The L group prolonged the in vivo BMP2/VEGF expression (up to 4 weeks), extended the antibody responses, and slightly enhanced the cell-mediated cytotoxicity. Nonetheless, the L group led to remarkably better bone healing and remodeling than the Mock and S groups. These data confirmed that the ASCs engineered with the hybrid BV imparted prolonged expression of BMP2/VEGF which, although stimulated low levels of humoral and cell-mediated immune responses, essentially augmented the healing of massive segmental bone defects.


Subject(s)
Adipose Tissue/cytology , Femur/immunology , Femur/pathology , Genetic Engineering , Stem Cell Transplantation , Stem Cells/immunology , Wound Healing/immunology , Animals , Antibodies/immunology , Apoptosis , Baculoviridae , Bone Morphogenetic Protein 2/metabolism , Bone Remodeling , Cell Movement , Cytotoxicity, Immunologic , Femur/diagnostic imaging , Humans , In Situ Hybridization, Fluorescence , Inflammation/pathology , Interferon-gamma/metabolism , Macrophages/cytology , Male , Rabbits , Stem Cells/cytology , Stem Cells/metabolism , T-Lymphocytes/cytology , Tomography, Emission-Computed, Single-Photon , Tomography, X-Ray Computed , Transgenes/genetics , Vascular Endothelial Growth Factor A/metabolism
13.
Tissue Eng Part A ; 18(19-20): 2114-24, 2012 Oct.
Article in English | MEDLINE | ID: mdl-22712565

ABSTRACT

Adipose-derived stem cells (ASCs) have captured growing interests for cartilage regeneration. Although ASCs chondrogenesis can be stimulated by genetic modification, whether genetically engineered ASCs hold promise for the cartilaginous tissue formation remains to be explored. Since baculovirus (an emerging gene delivery vector) effectively transduced ASCs and transforming growth factor ß3 (TGF-ß3) was recently shown to induce ASCs chondrogenesis more potently than TGF-ß1, we constructed a baculoviral vector (Bac-CT3W) to encode TGF-ß3. The Bac-CT3W-transduced ASCs expressed TGF-ß3 robustly and substantiated the chondrogenesis of ASCs cultured in monolayer and in porous scaffolds. Culture of the transduced cell/scaffold constructs in the rotating-shaft bioreactor (RSB) under hypoxic and perfusion conditions for 2 weeks further augmented the ASCs chondrogenesis and deposition of cartilage-specific collagen II and glycosaminoglycans, leading to the formation of cartilage-like tissues with hyaline appearance and compressive modulus approaching 62% of the native articular cartilage. Intriguingly, prolonged culture to 3 or 4 weeks failed to further augment the construct growth, probably due to the scaffold degradation. Altogether, baculovirus-mediated TGF-ß3 expression in ASCs in conjunction with dynamic culture in the RSB for 2 weeks synergistically ameliorated the ASCs chondrogenesis and formation of cartilaginous tissues, representing a novel approach to producing engineered cartilages.


Subject(s)
Bioreactors , Cartilage/cytology , Cell Differentiation/physiology , Chondrogenesis/physiology , Stem Cells/cytology , Transforming Growth Factor beta3/metabolism , Adipose Tissue/cytology , Cells, Cultured , Immunohistochemistry , Stem Cells/metabolism , Tissue Engineering
14.
Biomaterials ; 33(27): 6559-69, 2012 Sep.
Article in English | MEDLINE | ID: mdl-22704844

ABSTRACT

Graphene oxide (GO) nanosheets have sparked growing interests in biological and medical applications. This study examined how macrophage, the primary immune cell type engaging microbes, responded to GO treatment. We uncovered that incubation of macrophage cell RAW264.7 with GO elicited autophagy in a concentration-dependent manner, as evidenced by the appearance of autophagic vacuoles and activation of autophagic marker proteins. Such GO-induced autophagy was observed in various cell lines and in macrophage treated with GO of different sizes. Strikingly, GO treatment of macrophage provoked the toll-like receptor (TLR) signaling cascades and triggered ensuing cytokine responses. Molecular analysis identified that TLR4 and TLR9 and their downstream signaling mediators MyD88, TRAF6 and NF-κB played pivotal roles in the GO-induced inflammatory responses. By silencing individual genes in the signaling pathway, we further unveiled that the GO-induced autophagy was modulated by TLR4, TLR9 and was dependent on downstream adaptor proteins MyD88, TRIF and TRAF6. Altogether, we demonstrated that GO treatment of cells simultaneously triggers autophagy and TLR4/TLR9-regulated inflammatory responses, and the autophagy was at least partly regulated by the TLRs pathway. This study thus suggests a mechanism by which cells respond to nanomaterials and underscores the importance of future safety evaluation of nanomaterials.


Subject(s)
Autophagy/drug effects , Graphite/pharmacology , Signal Transduction/drug effects , Toll-Like Receptors/metabolism , Animals , Cell Line , Cytokines/metabolism , Gene Silencing/drug effects , Macrophages/cytology , Macrophages/drug effects , Macrophages/metabolism , Macrophages/ultrastructure , Mice , Models, Biological , Nanoparticles/chemistry , Vacuoles/drug effects , Vacuoles/metabolism , Vacuoles/ultrastructure
15.
Biomaterials ; 33(14): 3682-92, 2012 May.
Article in English | MEDLINE | ID: mdl-22361095

ABSTRACT

Repair of large calvarial bony defects remains clinically challenging because successful spontaneous calvarial re-ossification rarely occurs. Although bone marrow-derived mesenchymal stem cells (BMSCs) genetically engineered with baculovirus (BV) for transient expression of osteogenic/angiogenic factors hold promise for bone engineering, we hypothesized that calvarial bone healing necessitates prolonged growth factor expression. Therefore, we employed a hybrid BV vector system whereby one BV expressed FLP while the other harbored the BMP2 (or VEGF) cassette flanked by Frt sequences. Transduction of rabbit BMSCs with the FLP/Frt-based BV vector led to FLP-mediated episome formation, which not only extended the BMP2/VEGF expression beyond 28 days but augmented the BMSCs osteogenesis. After allotransplantation into rabbits, X-ray, PET/CT, µCT and histological analyses demonstrated that the sustained BMP2/VEGF expression remarkably ameliorated the angiogenesis and regeneration of critical-size (8 mm) calvarial defects, when compared with the group implanted with BMSCs transiently expressing BMP2/VEGF. The prolonged expression by BMSCs accelerated the bone remodeling and regenerated the bone through the natural intramembranous pathway, filling ≈83% of the area and ≈63% of the volume in 12 weeks. These data implicated the potential of the hybrid BV vector to engineer BMSCs for sustained BMP2/VEGF expression and the repair of critical-size calvarial defects.


Subject(s)
Bone Regeneration , Growth Substances/genetics , Mesenchymal Stem Cell Transplantation/methods , Skull/injuries , Animals , Baculoviridae/genetics , Bone Morphogenetic Protein 2/biosynthesis , Bone Morphogenetic Protein 2/genetics , Bone Regeneration/drug effects , Bone Regeneration/genetics , Bone Regeneration/physiology , Bone Remodeling/drug effects , Bone Remodeling/genetics , Bone Remodeling/physiology , Female , Gene Expression , Growth Substances/biosynthesis , Materials Testing , Mesenchymal Stem Cells/metabolism , Osteogenesis/drug effects , Osteogenesis/genetics , Osteogenesis/physiology , Rabbits , Recombinant Proteins/biosynthesis , Recombinant Proteins/genetics , Skull/pathology , Skull/surgery , Tissue Scaffolds , Vascular Endothelial Growth Factor A/biosynthesis , Vascular Endothelial Growth Factor A/genetics
16.
Curr Gene Ther ; 10(3): 242-54, 2010 Jun.
Article in English | MEDLINE | ID: mdl-20426760

ABSTRACT

Baculovirus is an effective vector for gene delivery into various mammalian cells, including chondrocytes and mesenchymal stem cells, and has been employed for diverse applications. By gene delivery and expression of the growth factor, recombinant baculovirus has been shown to modulate the differentiation state of the cells and stimulates the production of extracellular matrix and tissue formation, hence repairing the damaged cartilage and bone in vivo. This article reviews the studies pertaining to the applications of baculovirus-mediated gene delivery in cartilage and bone tissue engineering and discusses recent progress, future applications and potential hurdles.


Subject(s)
Baculoviridae/genetics , Gene Transfer Techniques , Genetic Therapy/methods , Tissue Engineering/methods , Animals , Baculoviridae/metabolism , Bone and Bones/metabolism , Cartilage/metabolism , Cell Differentiation/genetics , Chondrocytes/cytology , Chondrocytes/metabolism , Extracellular Matrix/genetics , Extracellular Matrix/metabolism , Genes , Genetic Vectors , Humans , Mesenchymal Stem Cells/cytology , Mesenchymal Stem Cells/metabolism
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