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1.
J R Soc Interface ; 20(207): 20230468, 2023 10.
Article in English | MEDLINE | ID: mdl-37817581

ABSTRACT

If it were possible to purchase tumour-spheroids as a standardised product, ready for direct use in assays, this may contribute to greater research reproducibility, potentially reducing costs and accelerating outcomes. Herein, we describe a workflow where uniformly sized cancer tumour-spheroids are mass-produced using microwell culture, cryopreserved with high viability, and then cultured in neutral buoyancy media for drug testing. C4-2B prostate cancer or MCF-7 breast cancer cells amalgamated into uniform tumour-spheroids after 48 h of culture. Tumour-spheroids formed from 100 cells each tolerated the cryopreservation process marginally better than tumour-spheroids formed from 200 or 400 cells. Post-thaw, tumour-spheroid metabolic activity was significantly reduced, suggesting mitochondrial damage. Metabolic function was rescued by thawing the tumour-spheroids into medium supplemented with 10 µM N-Acetyl-l-cysteine (NAC). Following thaw, the neutral buoyancy media, Happy Cell ASM, was used to maintain tumour-spheroids as discrete tissues during drug testing. Fresh and cryopreserved C4-2B or MCF-7 tumour-spheroids responded similarly to titrations of Docetaxel. This protocol will contribute to a future where tumour-spheroids may be available for purchase as reliable and reproducible products, allowing laboratories to efficiently replicate and build on published research, in many cases, making tumour-spheroids simply another cell culture reagent.


Subject(s)
Breast Neoplasms , Spheroids, Cellular , Male , Humans , Reproducibility of Results , Drug Evaluation, Preclinical , Cryopreservation/methods
2.
Sci Rep ; 13(1): 15030, 2023 09 12.
Article in English | MEDLINE | ID: mdl-37699961

ABSTRACT

Cystic fibrosis transmembrane conductance regulator modulators have revolutionized cystic fibrosis (CF) care in the past decade. This study explores the CF-related mortality trends in the US from 1999 to 2020. We extracted CF-related mortality data from the CDC WONDER database. CF age-standardized mortality rates (ASMRs) were identified by ICD-10 code E84 and were stratified by demographic and geographical variables. Temporal trends were analyzed using Joinpoint modeling. CF-related ASMRs decreased from 1.9 to 1.04 per million population (p = 0.013), with a greater reduction in recent years. This trend was replicated in both sexes. The median age of death increased from 24 to 37 years. CF mortality rates decreased across sex, white race, non-Hispanic ethnicity, census regions, and urbanization status. Incongruent trends were reported in non-white races and Hispanic ethnicity. A lower median age of death was observed in women, non-white races, and Hispanic ethnicity. SARS-CoV-2 infection was the primary cause of death in 1.7% of CF decedents in 2020. The national CF-related mortality rates declined and the median age of death among CF decedents increased significantly indicating better survival in the recent years. The changes were relatively slow during the earlier period of the study, followed by a greater decline lately. We observed patterns of sex, ethnic, racial, and geographical disparities associated with the worsening of the gap between ethnicities, narrowing of the gap between races and rural vs. urban counties, and closing of the gap between sexes over the study period.


Subject(s)
COVID-19 , Cystic Fibrosis , Male , Humans , United States/epidemiology , Female , Young Adult , Adult , SARS-CoV-2 , Ethnicity , White
3.
J Tissue Eng ; 14: 20417314231176901, 2023.
Article in English | MEDLINE | ID: mdl-37529249

ABSTRACT

The financial viability of a cell and tissue-engineered therapy may depend on the compatibility of the therapy with mass production and cryopreservation. Herein, we developed a method for the mass production and cryopreservation of 3D cartilage microtissues. Cartilage microtissues were assembled from either 5000 human bone marrow-derived stromal cells (BMSC) or 5000 human articular chondrocytes (ACh) each using a customized microwell platform (the Microwell-mesh). Microtissues rapidly accumulate homogenous cartilage-like extracellular matrix (ECM), making them potentially useful building blocks for cartilage defect repair. Cartilage microtissues were cultured for 5 or 10 days and then cryopreserved in 90% serum plus 10% dimethylsulfoxide (DMSO) or commercial serum-free cryopreservation media. Cell viability was maximized during thawing by incremental dilution of serum to reduce oncotic shock, followed by washing and further culture in serum-free medium. When assessed with live/dead viability dyes, thawed microtissues demonstrated high viability but reduced immediate metabolic activity relative to unfrozen control microtissues. To further assess the functionality of the freeze-thawed microtissues, their capacity to amalgamate into a continuous tissue was assess over a 14 day culture. The amalgamation of microtissues cultured for 5 days was superior to those that had been cultured for 10 days. Critically, the capacity of cryopreserved microtissues to amalgamate into a continuous tissue in a subsequent 14-day culture was not compromised, suggesting that cryopreserved microtissues could amalgamate within a cartilage defect site. The quality ECM was superior when amalgamation was performed in a 2% O2 atmosphere than a 20% O2 atmosphere, suggesting that this process may benefit from the limited oxygen microenvironment within a joint. In summary, cryopreservation of cartilage microtissues is a viable option, and this manipulation can be performed without compromising tissue function.

4.
J Tissue Eng ; 14: 20417314231177136, 2023.
Article in English | MEDLINE | ID: mdl-37362901

ABSTRACT

For bone marrow stromal cells (BMSC) to be useful in cartilage repair their propensity for hypertrophic differentiation must be overcome. A single day of TGF-ß1 stimulation activates intrinsic signaling cascades in BMSCs which subsequently drives both chondrogenic and hypertrophic differentiation. TGF-ß1 stimulation upregulates SP7, a transcription factor known to contribute to hypertrophic differentiation, and SP7 remains upregulated even if TGF-ß1 is subsequently withdrawn from the chondrogenic induction medium. Herein, we stably transduced BMSCs to express an shRNA designed to silence SP7, and assess the capacity of SP7 silencing to mitigate hypertrophy. SP7 silencing dampened both hypertrophic and chondrogenic differentiation processes, resulting in diminished microtissue size, impaired glycosaminoglycan production and reduced chondrogenic and hypertrophic gene expression. Thus, while hypertrophic features were dampened by SP7 silencing, chondrogenic differentation was also compromised. We further investigated the role of SP7 in monolayer osteogenic and adipogenic cultures, finding that SP7 silencing dampened characteristic mineralization and lipid vacuole formation, respectively. Overall, SP7 silencing affects the trilineage differentiation of BMSCs, but is insufficient to decouple BMSC hypertrophy from chondrogenesis. These data highlight the challenge of promoting BMSC chondrogenesis whilst simultaneously reducing hypertrophy in cartilage tissue engineering strategies.

6.
Cells ; 13(1)2023 12 23.
Article in English | MEDLINE | ID: mdl-38201241

ABSTRACT

Chondrogenic induction of bone-marrow-derived stromal cells (BMSCs) is typically accomplished with medium supplemented with growth factors (GF) from the transforming growth factor-beta (TGF-ß)/bone morphogenetic factor (BMP) superfamily. In a previous study, we demonstrated that brief (1-3 days) stimulation with TGF-ß1 was sufficient to drive chondrogenesis and hypertrophy using small-diameter microtissues generated from 5000 BMSC each. This biology is obfuscated in typical large-diameter pellet cultures, which suffer radial heterogeneity. Here, we investigated if brief stimulation (2 days) of BMSC microtissues with BMP-2 (100 ng/mL) or growth/differentiation factor (GDF-5, 100 ng/mL) was also sufficient to induce chondrogenic differentiation, in a manner comparable to TGF-ß1 (10 ng/mL). Like TGF-ß1, BMP-2 and GDF-5 are reported to stimulate chondrogenic differentiation of BMSCs, but the effects of transient or brief use in culture have not been explored. Hypertrophy is an unwanted outcome in BMSC chondrogenic differentiation that renders engineered tissues unsuitable for use in clinical cartilage repair. Using three BMSC donors, we observed that all GFs facilitated chondrogenesis, although the efficiency and the necessary duration of stimulation differed. Microtissues treated with 2 days or 14 days of TGF-ß1 were both superior at producing extracellular matrix and expression of chondrogenic gene markers compared to BMP-2 and GDF-5 with the same exposure times. Hypertrophic markers increased proportionally with chondrogenic differentiation, suggesting that these processes are intertwined for all three GFs. The rapid action, or "temporal potency", of these GFs to induce BMSC chondrogenesis was found to be as follows: TGF-ß1 > BMP-2 > GDF-5. Whether briefly or continuously supplied in culture, TGF-ß1 was the most potent GF for inducing chondrogenesis in BMSCs.


Subject(s)
Mesenchymal Stem Cells , Transforming Growth Factor beta1 , Humans , Transforming Growth Factor beta1/pharmacology , Growth Differentiation Factor 5/pharmacology , Bone Marrow , Chondrogenesis , Transforming Growth Factor beta , Hypertrophy
7.
Respir Med Case Rep ; 38: 101672, 2022.
Article in English | MEDLINE | ID: mdl-35651518

ABSTRACT

Bordetella bronchiseptica is a pleomorphic gram-negative coccobacillus that commonly causes respiratory tract infections in canines, felines, and swine. Human infections are rare. We report a case of Bordetella bronchiseptica pneumonia in a 67-year-old immunocompromised host. His past medical history included multiple myeloma treated with autologous bone marrow transplant followed by a chimeric antigen receptor cell therapy for relapse. He was admitted with unrelenting diarrhea due to HHV-6 pancolitis. During the hospital course he developed high-grade fever (102.3°F), cough and respiratory failure requiring mechanical ventilation. Chest imaging demonstrated bilateral opacities most pronounced at lung bases and worsening mediastinal lymphadenopathy. Bronchoalveolar lavage cultures grew Bordetella bronchiseptica. He was treated with piperacillin/tazobactam, but developed progressive multiorgan failure, transitioned to comfort care, and expired in the hospital. Bordetella bronchiseptica is an organism that do not cause serious infection in immunocompetent persons but can sometimes cause serious illness in immunocompromised populations. It causes "kennel cough" in dogs and spready by respiratory droplets. Dogs and cats are not uniformly vaccinated against this pathogen. Therefore, transmission through animal contact is becoming increasingly common. Realize that unlike other Bordetella spp, this pathogen is not typically responsive to erythromycin and is often resistant to ampicillin and cephalosporins so the typical neutropenic fever coverage with an antipseudomonal cephalosporin and azithromycin might not be effective. Given the increasing recognition of this zoonosis as a threat to the immunocompromised, it is essential to educate immunocompromised patients to minimize zoonotic exposure, as immunization of pets might not confer protection to humans.

8.
Stem Cell Reports ; 17(3): 616-632, 2022 03 08.
Article in English | MEDLINE | ID: mdl-35180395

ABSTRACT

Bone morphogenetic protein (BMP) cascades are upregulated during bone marrow-derived stromal cell (BMSC) chondrogenesis, contributing to hypertrophy and preventing effective BMSC-mediated cartilage repair. Previous work demonstrated that a proprietary BMP inhibitor prevented BMSC hypertrophy, yielding stable cartilage tissue. Because of the significant therapeutic potential of a molecule capable of hypertrophy blockade, we evaluated the capacity of a commercially available BMP type I receptor inhibitor with similar properties, LDN 193189, to prevent BMSC hypertrophy. Using 14-day microtissue chondrogenic induction cultures we found that LDN 193189 permitted BMSC chondrogenesis but did not prevent hypertrophy. LDN 193189 was sufficiently potent to counter mineralization and adipogenesis in response to exogenous BMP-2 in osteogenic induction cultures. LDN 193189 did not modify BMSC behavior in adipogenic induction cultures. Although LDN 193189 is effective in countering BMP signaling in a manner that influences BMSC fate, this blockade is insufficient to prevent hypertrophy.


Subject(s)
Chondrogenesis , Mesenchymal Stem Cells , Bone Marrow Cells/metabolism , Bone Morphogenetic Proteins/metabolism , Cell Differentiation/physiology , Humans , Hypertrophy/metabolism , Osteogenesis , Pyrazoles , Pyrimidines
9.
PLoS One ; 15(12): e0242945, 2020.
Article in English | MEDLINE | ID: mdl-33370348

ABSTRACT

BACKGROUND: Emerging data suggests a possible role for cysteamine as an adjunct treatment for pulmonary exacerbations of cystic fibrosis (CF) that continue to be a major clinical challenge. There are no studies investigating the use of cysteamine in pulmonary exacerbations of CF. This exploratory randomized clinical trial was conducted to answer the question: In future pivotal trials of cysteamine as an adjunct treatment in pulmonary exacerbations of CF, which candidate cysteamine dosing regimens should be tested and which are the most appropriate, clinically meaningful outcome measures to employ as endpoints? METHODS AND FINDINGS: Multicentre double-blind randomized clinical trial. Adults experiencing a pulmonary exacerbation of CF being treated with standard care that included aminoglycoside therapy were randomized equally to a concomitant 14-day course of placebo, or one of 5 dosing regimens of cysteamine. Outcomes were recorded on days 0, 7, 14 and 21 and included sputum bacterial load and the patient reported outcome measures (PROMs): Chronic Respiratory Infection Symptom Score (CRISS), the Cystic Fibrosis Questionnaire-Revised (CFQ-R); FEV1, blood leukocyte count, and inflammatory markers. Eighty nine participants in fifteen US and EU centres were randomized, 78 completed the 14-day treatment period. Cysteamine had no significant effect on sputum bacterial load, however technical difficulties limited interpretation. The most consistent findings were for cysteamine 450mg twice daily that had effects additional to that observed with placebo, with improved symptoms, CRISS additional 9.85 points (95% CI 0.02, 19.7) p = 0.05, reduced blood leukocyte count by 2.46x109 /l (95% CI 0.11, 4.80), p = 0.041 and reduced CRP by geometric mean 2.57 nmol/l (95% CI 0.15, 0.99), p = 0.049. CONCLUSION: In this exploratory study cysteamine appeared to be safe and well-tolerated. Future pivotal trials investigating the utility of cysteamine in pulmonary exacerbations of CF need to include the cysteamine 450mg doses and CRISS and blood leukocyte count as outcome measures. CLINICAL TRIAL REGISTRATION: NCT03000348; www.clinicaltrials.gov.


Subject(s)
Cysteamine/administration & dosage , Cysteamine/therapeutic use , Cystic Fibrosis/drug therapy , Lung/drug effects , Administration, Oral , Adult , Cysteamine/adverse effects , Female , Humans , Male , Medication Adherence , Safety
10.
Crit Care Explor ; 2(10): e0235, 2020 Oct.
Article in English | MEDLINE | ID: mdl-33134936

ABSTRACT

During training, fellows serve as teachers and role models for junior colleagues. Fellows-as-teachers curricula may support these roles, but little is known about their effectiveness and durability. We sought to measure the long-term effects on ICU rounds after administering fellows-as-teachers workshops. DESIGN: Prospective pre-/postintervention observational study of ICU rounds. SETTING: Tertiary-care medical ICU with both pulmonary critical care and critical care medicine fellowships. SUBJECTS: ICU teaching teams. INTERVENTIONS: Fellows attended immersive workshops on promoting clinical reasoning, managing the learning environment, teaching bedside skills, and developing situational awareness on ICU rounds. After the workshops, faculty physicians were encouraged to have fellows routinely lead afternoon rounds. MEASUREMENTS AND MAIN RESULTS: We gathered data from direct observations of ICU rounding activities, residents' evaluations of rounds from surveys, and faculty physicians' written comments on fellows' performance in the ICU from end-of-rotation evaluations. Data were analyzed using descriptive statistics, nonparametric comparative tests, and chi-square tests for categorical data. A total of 61 ICU rounding sessions were observed with 501 discrete provider-patient interactions. Survey responses were collected from a total of 53 residents preintervention and 34 residents postintervention. We reviewed 72 open-ended faculty comments on fellows' end-of-rotation evaluations, with 22 occurring postintervention. During the postintervention period, fellows were significantly more likely to make clinical decisions, explain their reasoning, provide teaching points, and ask questions on rounds. Additionally, we observed significantly higher quality written feedback on end-of-rotation evaluations by faculty physicians. However, residents generally harbored neutral or negative perceptions about the educational value of fellow-led rounds postintervention. CONCLUSIONS: Fellows' contributions to patient care and teaching on ICU rounds increased for several months after our fellows-as-teachers workshops. Despite limitations and contamination in our design, our data suggest that similarly designed curricula may promote fellow engagement, possibly at the expense of residents' education.

12.
Microbiol Resour Announc ; 8(13)2019 Mar 28.
Article in English | MEDLINE | ID: mdl-30923238

ABSTRACT

Here, we report the draft whole-genome sequence of Bacillus lehensis M136, isolated from a hyperalkaline spring located in Pangasinan, Philippines. From 24 scaffolds, the total genome assembly length is 3,985,437 bp. Industrially important genes like cyclodextrin glycosyltransferase (CGTase) and proteases were detected in this draft genome.

14.
BMJ Case Rep ; 20172017 Jun 18.
Article in English | MEDLINE | ID: mdl-28630242

ABSTRACT

A 53-year-old man with a history of Crohn's disease on infliximab, presented with several weeks of cough and dyspnoea. He had a right-sided pleural effusion, found to be exudative with lymphocytic predominance. He underwent right-sided video-assisted thoracic surgery (VATS) with biopsies and pleurodesis. Histopathology showed pleural-based non-caseating granulomas with unremarkable lung parenchyma. Cultures were only positive for Propionibacterium acnes 8 months later, he was found to have a left-sided exudative, lymphocytic predominant pleural effusion. Left-sided VATS and biopsies again showed pleural-based non-caseating granulomas with normal lung parenchyma. Having ruled out an active infection and malignant lesions, we diagnosed infliximab-induced pleural granulomas. Infliximab was stopped. The patient continues to do well at 6 years of follow-up. We believe this is the first report of tumour necrosis factor (TNF) inhibitor-induced isolated pleural granulomas. P. acnes and cytokine imbalance might be responsible for the pathogenesis of TNF inhibitor-induced granulomas.


Subject(s)
Crohn Disease/drug therapy , Gastrointestinal Agents/adverse effects , Gram-Positive Bacterial Infections/chemically induced , Granuloma/chemically induced , Infliximab/adverse effects , Pleural Effusion/chemically induced , Tumor Necrosis Factor-alpha/antagonists & inhibitors , Cough , Dyspnea , Gastrointestinal Agents/therapeutic use , Gram-Positive Bacterial Infections/physiopathology , Gram-Positive Bacterial Infections/therapy , Granuloma/physiopathology , Granuloma/therapy , Humans , Infliximab/therapeutic use , Male , Middle Aged , Pleural Effusion/physiopathology , Pleural Effusion/therapy , Pleurodesis , Propionibacterium acnes/isolation & purification , Thoracic Surgery, Video-Assisted , Time Factors , Treatment Outcome
16.
Sleep Disord ; 2014: 798487, 2014.
Article in English | MEDLINE | ID: mdl-24693440

ABSTRACT

Complex sleep apnea is the term used to describe a form of sleep disordered breathing in which repeated central apneas (>5/hour) persist or emerge when obstructive events are extinguished with positive airway pressure (PAP) and for which there is not a clear cause for the central apneas such as narcotics or systolic heart failure. The driving forces in the pathophysiology are felt to be ventilator instability associated oscillation in PaCO2 arterial partial pressure of Carbon Dioxide, continuous cositive airway pressure (CPAP) related increased CO2 carbon dioxide elimination, and activation of airway and pulmonary stretch receptors triggering these central apneas. The prevalence ranges from 0.56% to 18% with no clear predictive characteristics as compared to simple obstructive sleep apnea. Prognosis is similar to obstructive sleep apnea. The central apnea component in most patients on followup using CPAP therap, has resolved. For those with continued central apneas on simple CPAP therapy, other treatment options include bilevel PAP, adaptive servoventilation, permissive flow limitation and/or drugs.

17.
ASAIO J ; 60(2): 216-23, 2014.
Article in English | MEDLINE | ID: mdl-24399056

ABSTRACT

In this study, a novel porous hydroxyapatite scaffold was designed and fabricated to imitate natural bone through a multipass extrusion process. The conceptual design manifested unidirectional microchannels at the exterior part of the scaffold to facilitate rapid biomineralization and a central canal that houses the bone marrow. External and internal fissures were minimized during microwave sintering at 1,100 °C. No deformation was noted, and a mechanically stable scaffold was fabricated. Detailed microstructure of the fabricated artificial bone was examined by scanning electron microscope and X-ray diffractometer, and material properties like compressive strength were evaluated. The initial biocompatibility was examined by the cell proliferation of MG-63 osteoblast-like cells using MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. Preliminary in vivo investigation in a rabbit model after 4 weeks and 8 weeks of implantation showed full osteointegration of the scaffold with the native tissue, and formation of bone tissue within the pore network, as examined by microcomputed tomography analyses and histological staining. Osteon-like bone microarchitecture was observed along the unidirectional channel with microblood vessels. These confirm a biomimetic regeneration model in the implanted bone scaffold, which can be used as an artificial alternative for damaged bone.


Subject(s)
Bone Regeneration/physiology , Durapatite , Guided Tissue Regeneration/instrumentation , Tissue Scaffolds , Animals , Biocompatible Materials , Bone and Bones , Cell Line , Compressive Strength , Guided Tissue Regeneration/methods , Humans , Male , Materials Testing , Microscopy, Electron, Scanning , Osteoblasts/cytology , Osteoblasts/metabolism , Porosity , Rabbits , X-Ray Diffraction
18.
J Biomater Appl ; 28(8): 1164-79, 2014 Apr.
Article in English | MEDLINE | ID: mdl-24014247

ABSTRACT

Electrospun polycaprolactone and poly(lacto-co-glycolide) membranes were loaded with biphasic calcium phosphate powder to facilitate osteoconductivity. Different concentrations of biphasic calcium phosphate powder were added to the polymer solution, and successful loading was confirmed by X-ray diffraction analysis, transmission electron microscope, and scanning electron microscope with energy-dispersive spectroscopy visualization. The effect of the added biphasic calcium phosphate on the polymer membrane was investigated in terms of the material's tensile strength and strain, in vitro cytocompatibility, and in vivo tissue regeneration. It was observed that the tensile strength of the membranes increased with the addition of the biphasic calcium phosphate powder. Immersion in simulated body fluid solution for seven days leads to the formation of apatite-like deposits in the fibers, which further improved the mechanical stability. Moreover, proliferation and adhesion of osteoblast-like cells were more apparent upon the addition of the biphasic calcium phosphate powder as seen with the increasing cell density from (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and micrographs from scanning electron microscope and confocal microscopy. Sample membranes were also implanted to investigate the membrane's ability to regenerate bone in a rat calvarium. Histological staining and micro-CT histomorphometric analyses showed neo-bone formation in the implanted rat skull.


Subject(s)
Bone Regeneration/drug effects , Bone Substitutes/administration & dosage , Bone Substitutes/chemistry , Hydroxyapatites/administration & dosage , Lactic Acid/chemistry , Polyesters/chemistry , Polyglycolic Acid/chemistry , Animals , Biomechanical Phenomena , Bone Substitutes/toxicity , Cell Adhesion/drug effects , Cell Line , Cell Proliferation/drug effects , Cell Survival/drug effects , Humans , Hydroxyapatites/chemistry , Hydroxyapatites/toxicity , Lactic Acid/toxicity , Male , Materials Testing , Microscopy, Electron, Scanning , Microscopy, Electron, Transmission , Nanofibers/chemistry , Nanofibers/toxicity , Nanofibers/ultrastructure , Osteoblasts/cytology , Osteoblasts/drug effects , Osteoblasts/physiology , Polyesters/toxicity , Polyglycolic Acid/toxicity , Polylactic Acid-Polyglycolic Acid Copolymer , Powder Diffraction , Rats , Rats, Sprague-Dawley , Skull/drug effects , Skull/physiology , Tensile Strength
19.
J Biomater Appl ; 28(5): 739-56, 2014 Jan.
Article in English | MEDLINE | ID: mdl-23470354

ABSTRACT

In this work, we fabricated injectable bone substitutes modified with the addition of bioactive glass powders synthesized via ultrasonic energy-assisted hydrothermal method to the calcium phosphate-based bone cement to improve its biocompatibility. The injectable bone substitutes was initially composed of a powder component (tetracalcium phosphate, dicalcium phosphate dihydrate and calcium sulfate dehydrate) and a liquid component (citric acid, chitosan and hydroxyl-propyl-methyl-cellulose) upon which various concentrations of bioactive glass were added: 0%, 10%, 20% and 30%. Setting time and compressive strength of the injectable bone substitutes were evaluated and observed to improve with the increase of bioactive glass content. Surface morphologies were observed via scanning electron microscope before and after submersion of the samples to simulated body fluid and increase in apatite formation was detected using x-ray diffraction machine. In vitro biocompatibility of the injectable bone substitutes was observed to improve with the addition of bioactive glass as the proliferation/adhesion behavior of cells on the material increased. Human gene markers were successfully expressed using real time-polymerase chain reaction and the samples were found to promote cell viability and be more biocompatible as the concentration of bioactive glass increases. In vivo biocompatibility of the samples containing 0% and 30% bioactive glass were evaluated using Micro-CT and histological staining after 3 months of implantation in male rabbits' femurs. No inflammatory reaction was observed and significant bone formation was promoted by the addition of bioactive glass to the injectable bone substitute system.


Subject(s)
Biocompatible Materials , Bone Regeneration , Bone Substitutes , Calcium Phosphates , Glass , Animals , Body Fluids , Cell Adhesion , Cell Line , Cell Proliferation , In Vitro Techniques , Materials Testing , Microscopy, Electron, Scanning , Rabbits , Real-Time Polymerase Chain Reaction , Spectroscopy, Fourier Transform Infrared , Surface Properties , X-Ray Microtomography
20.
J Biomed Mater Res B Appl Biomater ; 101(6): 1095-105, 2013 Aug.
Article in English | MEDLINE | ID: mdl-23564699

ABSTRACT

A biodegradable fibrous tube was fabricated by electrospinning method using a combination of Poly(lactic-co-glycolic acid) (PLGA) and gelatin dissolved in trifluoroethanol (TFE). Different ratios of the two polymers (PLGA/Gelatin: 1/9, 3/7, 5/5) were used for electrospinning to determine the optimum condition appropriate for intestinal stent application. Fiber morphology was visualized and analyzed using a scanning electron microscope (SEM). Characterizations of physical properties were done according to its tensile strength, surface hydrophilicity, swelling ability, and biodegradability. Biocompatibility of the scaffolds was investigated in vitro using IEC-18 (Rat intestinal epithelial cell). Cell proliferation was quantified using MTT assay and cell adhesion behavior was visualized by SEM and confocal laser scanning microscope. PLGA/Gelatin (5/5) was determined to have adequate material properties and sufficient in vitro biocompatibility. This was then implanted in a male Sprague-Dawley rat for 14 days to determine in vivo behavior of the sample. Histological examination on the intestinal tissue surrounding the graft showed normal morphology comparable to non-implanted intestine.


Subject(s)
Biocompatible Materials/chemistry , Gelatin/chemistry , Lactic Acid/chemistry , Polyglycolic Acid/chemistry , Stents , Absorbable Implants , Anastomosis, Surgical , Animals , Cell Proliferation , Intestinal Mucosa/cytology , Intestines/cytology , Intestines/surgery , Male , Materials Testing , Polylactic Acid-Polyglycolic Acid Copolymer , Rats
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