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1.
Biomed Microdevices ; 21(4): 94, 2019 11 04.
Artigo em Inglês | MEDLINE | ID: mdl-31686216

RESUMO

Nowadays, cancer disease is continuously identified as the leading cause of mortality worldwide. Cancer chemotherapeutic agents have been continuously developing to achieve high curative effectiveness and low side effects. However, solid tumors present the properties of low drug penetration and resistance of quiescent cells. Radiation therapy is concurrently given in some cases; but it induces different levels of adverse effects. In the current work, uniform sized multicellular spheroids were raised by microwell arrays to mimic the architecture of solid tumors. Investigation of the response of the spheroids was conducted after the treatment of alternating electric field. The result showed that the electric field could induce early apoptosis by disturbing cell membrane. Moreover, combined treatment of electric field and anti-cancer drug was applied to the spheroids. The electric field synergistically enhanced the treatment efficacy because the anti-cancer drug could permeate through the disrupted cell membrane. Significant improvement of late apoptosis was shown by the combined treatment. Because the electric field treatment induces limited side effect to the patient, lower dosage of anti-cancer drug may be applied to the patients for achieving curative effectiveness.


Assuntos
Antineoplásicos/farmacologia , Técnicas de Cultura de Células/instrumentação , Eletricidade , Esferoides Celulares/efeitos dos fármacos , Análise Serial de Tecidos/instrumentação , Linhagem Celular Tumoral , Terapia Combinada , Relação Dose-Resposta a Droga , Doxorrubicina/farmacologia , Células HeLa , Humanos , Esferoides Celulares/patologia
2.
Sensors (Basel) ; 20(1)2019 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-31905995

RESUMO

Chronic obstructive pulmonary disease (COPD) claimed 3.0 million lives in 2016 and ranked 3rd among the top 10 global causes of death. Moreover, once diagnosed and discharged from the hospital, the 30-day readmission risk in COPD patients is found to be the highest among all chronic diseases. The existing diagnosis methods, such as Global Initiative for Chronic Obstructive Lung Disease (GOLD) 2019, Body-mass index, airflow Obstruction, Dyspnea, and Exercise (BODE) index, modified Medical Research Council (mMRC), COPD assessment test (CAT), 6-minute walking distance, which are adopted currently by physicians cannot predict the potential readmission of COPD patients, especially within the 30 days after discharge from the hospital. In this paper, a statistical model was proposed to predict the readmission risk of COPD patients within 30-days by monitoring their physical activity (PA) in daily living with accelerometer-based wrist-worn wearable devices. This proposed model was based on our previously reported PA models for activity index (AI) and regularity index (RI) and it introduced a new parameter, quality of activity (QoA), which incorporates previously proposed parameters, such as AI and RI, with other activity-based indices to predict the readmission risk. Data were collected from continuous PA monitoring of 16 COPD patients after hospital discharge as test subjects and readmission prediction criteria were proposed, with a 63% sensitivity and a 37.78% positive prediction rate. Compared to other clinical assessment, diagnosis, and prevention methods, the proposed model showed significant improvement in predicting the 30-day readmission risk.


Assuntos
Acelerometria/instrumentação , Monitorização Fisiológica/instrumentação , Readmissão do Paciente , Doença Pulmonar Obstrutiva Crônica/diagnóstico , Serviço Hospitalar de Emergência , Humanos
3.
Sensors (Basel) ; 18(10)2018 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-30347695

RESUMO

In this work, a wearable smart clothing system for cardiac health monitoring with a multi-channel mechanocardiogram (MCG) has been developed to predict the myo-cardiac left ventricular ejection fraction (LVEF) function and to provide early risk warnings to the subjects. In this paper, the realization of the core of this system, i.e., the Cardiac Health Assessment and Monitoring Platform (CHAMP), with respect to its hardware, firmware, and wireless design features, is presented. The feature values from the CHAMP system have been correlated with myo-cardiac functions obtained from actual heart failure (HF) patients. The usability of this MCG-based cardiac health monitoring smart clothing system has also been evaluated with technology acceptance model (TAM) analysis and the results indicate that the subject shows a positive attitude toward using this wearable MCG-based cardiac health monitoring and early warning system.


Assuntos
Eletrocardiografia/métodos , Coração/fisiopatologia , Monitorização Fisiológica/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Arritmias Cardíacas/diagnóstico , Arritmias Cardíacas/fisiopatologia , Vestuário , Feminino , Insuficiência Cardíaca/diagnóstico , Insuficiência Cardíaca/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Processamento de Sinais Assistido por Computador/instrumentação , Tecnologia/métodos , Dispositivos Eletrônicos Vestíveis , Adulto Jovem
4.
Sensors (Basel) ; 18(2)2018 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-29382098

RESUMO

Cardiovascular disease (CVD) is a major public concern and socioeconomic problem across the globe. The popular high-end cardiac health monitoring systems such as magnetic resonance imaging (MRI), computerized tomography scan (CT scan), and echocardiography (Echo) are highly expensive and do not support long-term continuous monitoring of patients without disrupting their activities of daily living (ADL). In this paper, the continuous and non-invasive cardiac health monitoring using unobtrusive sensors is explored aiming to provide a feasible and low-cost alternative to foresee possible cardiac anomalies in an early stage. It is learned that cardiac health monitoring based on sole usage of electrocardiogram (ECG) signals may not provide powerful insights as ECG provides shallow information on various cardiac activities in the form of electrical impulses only. Hence, a novel low-cost, non-invasive seismocardiogram (SCG) signal along with ECG signals are jointly investigated for the robust cardiac health monitoring. For this purpose, the in-laboratory data collection model is designed for simultaneous acquisition of ECG and SCG signals followed by mechanisms for the automatic delineation of relevant feature points in acquired ECG and SCG signals. In addition, separate feature points based novel approach is adopted to distinguish between normal and abnormal morphology in each ECG and SCG cardiac cycle. Finally, a combined analysis of ECG and SCG is carried out by designing a Naïve Bayes conditional probability model. Experiments on Institutional Review Board (IRB) approved licensed ECG/SCG signals acquired from real subjects containing 12,000 cardiac cycles show that the proposed feature point delineation mechanisms and abnormal morphology detection methods consistently perform well and give promising results. In addition, experimental results show that the combined analysis of ECG and SCG signals provide more reliable cardiac health monitoring compared to the standalone use of ECG and SCG.


Assuntos
Coração , Atividades Cotidianas , Arritmias Cardíacas , Teorema de Bayes , Eletrocardiografia , Humanos
5.
Sensors (Basel) ; 17(4)2017 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-28353681

RESUMO

Use of information and communication technology such as smart phone, smart watch, smart glass and portable health monitoring devices for healthcare services has made Mobile Health (mHealth) an emerging research area. Coronary Heart Disease (CHD) is considered as a leading cause of death world wide and an increasing number of people die prematurely due to CHD. Under such circumstances, there is a growing demand for a reliable cardiac monitoring system to catch the intermittent abnormalities and detect critical cardiac behaviors which lead to sudden death. Use of mobile devices to collect Electrocardiography (ECG), Seismocardiography (SCG) data and efficient analysis of those data can monitor a patient's cardiac activities for early warning. This paper presents a novel cardiac data acquisition method and combined analysis of Electrocardiography (ECG) and multi channel Seismocardiography (SCG) data. An early warning system is implemented to monitor the cardiac activities of a person and accuracy assessment of the early warning system is conducted for the ECG data only. The assessment shows 88% accuracy and effectiveness of our proposed analysis, which implies the viability and applicability of the proposed early warning system.


Assuntos
Coração , Arritmias Cardíacas , Eletrocardiografia , Humanos , Smartphone , Telemedicina
6.
Sensors (Basel) ; 16(12)2016 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-27999324

RESUMO

Body posture and activity are important indices for assessing health and quality of life, especially for elderly people. Therefore, an easily wearable device or instrumented garment would be valuable for monitoring elderly people's postures and activities to facilitate healthy aging. In particular, such devices should be accepted by elderly people so that they are willing to wear it all the time. This paper presents the design and development of a novel, textile-based, intelligent wearable vest for real-time posture monitoring and emergency warnings. The vest provides a highly portable and low-cost solution that can be used both indoors and outdoors in order to provide long-term care at home, including health promotion, healthy aging assessments, and health abnormality alerts. The usability of the system was verified using a technology acceptance model-based study of 50 elderly people. The results indicated that although elderly people are anxious about some newly developed wearable technologies, they look forward to wearing this instrumented posture-monitoring vest in the future.


Assuntos
Modelos Teóricos , Monitorização Ambulatorial , Postura/fisiologia , Tecnologia , Dispositivos Eletrônicos Vestíveis , Desenho de Equipamento , Humanos , Doença de Parkinson/diagnóstico , Reprodutibilidade dos Testes , Processamento de Sinais Assistido por Computador , Têxteis
7.
Ann Plast Surg ; 74 Suppl 2: S168-72, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25695446

RESUMO

BACKGROUND: Mastication function is related to mandible movement, muscle strength, and bite force. No standard device for measuring bite force has been developed. A linear relationship between electromyographic activity and bite force has been reported by several investigators, but data on the reliability of this relationship remain limited in Asian young adults. AIM AND OBJECTIVES: The purpose of this study was to develop a clinically applicable, reliable, quantitative, and noninvasive system to measure the kinetic mastication function and observe the correlation between surface electromyography (sEMG) and bite force. MATERIALS AND METHODS: The study group consisted of 41 young healthy adults (24 men and 17 women). Surface electromyography was used to evaluate bilateral temporalis and masseter muscle activities, and an occlusal bite force system was used concurrently to measure the bite force during maximal voluntary biting. Bilateral symmetry was compared, and the correlation between EMG and bite force was calculated. RESULTS: The sEMG signals were 107.7±55.0 µV and 106.0±56.0 µV (P=0.699) on right and left temporalis muscles and 183.7±86.2 µV and 194.8±94.3 µV (P=0.121) on right and left masseter muscles, respectively. The bite force was 5.0±3.2 kg on the right side and 5.7±4.0 kg on the left side (P=0.974). A positive correlation between sEMG and bite force was observed. The correlation coefficient between the temporalis muscle and bite force was 0.512, and that between the masseter muscle and bite force was 0.360. CONCLUSION: No significant difference between the bilateral electromyographic activities of the temporalis and masseter muscles and bilateral bite force was observed in young healthy adults in Taiwan. A positive correlation between sEMG signals and bite force was noted. By combining sEMG and bite force, we developed a clinically applicable, quantitative, reliable, and noninvasive system for evaluating mastication function by using characteristics of biofeedback.


Assuntos
Força de Mordida , Eletromiografia/métodos , Mastigação/fisiologia , Adulto , Povo Asiático , Feminino , Humanos , Masculino , Músculo Masseter/fisiologia , Músculo Temporal/fisiologia , Adulto Jovem
8.
Biosensors (Basel) ; 12(6)2022 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-35735522

RESUMO

Accelerometer-based devices have been employed in seismocardiography fiducial point detection with the aid of quasi-synchronous alignment between echocardiography images and seismocardiogram signals. However, signal misalignments have been observed, due to the heartbeat cycle length variation. This paper not only analyzes the misalignments and detection errors but also proposes to mitigate the issues by introducing reference signals and adynamic time warping (DTW) algorithm. Two diagnostic parameters, the ratio of pre-ejection period to left ventricular ejection time (PEP/LVET) and the Tei index, were examined with two statistical verification approaches: (1) the coefficient of determination (R2) of the parameters versus the left ventricular ejection fraction (LVEF) assessments, and (2) the receiver operating characteristic (ROC) classification to distinguish the heart failure patients with reduced ejection fraction (HFrEF). Favorable R2 values were obtained, R2 = 0.768 for PEP/LVET versus LVEF and R2 = 0.86 for Tei index versus LVEF. The areas under the ROC curve indicate the parameters that are good predictors to identify HFrEF patients, with an accuracy of more than 92%. The proof-of-concept experiments exhibited the effectiveness of the DTW-based quasi-synchronous alignment in seismocardiography fiducial point detection. The proposed approach may enable the standardization of the fiducial point detection and the signal template generation. Meanwhile, the program-generated annotation data may serve as the labeled training set for the supervised machine learning.


Assuntos
Insuficiência Cardíaca , Função Ventricular Esquerda , Computadores , Ecocardiografia , Humanos , Volume Sistólico
9.
Biosensors (Basel) ; 11(11)2021 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-34821644

RESUMO

Accelerometer-based motion sensing has been extensively applied to fall detection. However, such applications can only detect fall accidents; therefore, a system that can prevent fall accidents is desirable. Bed falls account for more than half of patient falls and are preceded by a clear warning indicator: the patient attempting to get out of bed. This study designed and implemented an Internet of Things module, namely, Bluetooth low-energy-enabled Accelerometer-based Sensing In a Chip-packaging (BASIC) module, with a tilt-sensing algorithm based on the patented low-complexity COordinate Rotation DIgital Computer (CORDIC)-based algorithm for tilt angle conversions. It is applied for detecting the postural changes (from lying down to sitting up) and to protect individuals at a high risk of bed falls by prompting caregivers to take preventive actions and assist individuals trying to get up. This module demonstrates how motion and tilt sensing can be applied to bed fall prevention. The module can be further miniaturized or integrated into a wearable device and commercialized in smart health-care applications for bed fall prevention in hospitals and homes.


Assuntos
Acidentes por Quedas , Internet das Coisas , Dispositivos Eletrônicos Vestíveis , Acelerometria , Acidentes por Quedas/prevenção & controle , Humanos , Movimento (Física)
10.
PLoS One ; 15(1): e0227270, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31929560

RESUMO

With advances in technology, wireless and sensor technologies represent a method for continuously recording people's biomedical signals, which may enhance the diagnosis and treatment of users' everyday health conditions. These technologies mostly target older adults. In this study, we examine a smart clothing system targeting clinically high-risk patients, including older adults with cardiovascular disease (31 outpatients) and older adults in general (81 participants), to obtain an understanding of the patients' perception of using wearable healthcare technologies. Given that technology anxiety has been shown to affect users' resistance to using new technology and that perceived ubiquity is considered a characteristic of wearable devices and other mobile wireless technologies, we included three external variables: i.e., technology anxiety, perceived ubiquity, and resistance to change, in addition to the traditional components of the technology acceptance model (TAM). The results of the hypothesized model showed that among older adults in general, technology anxiety had a negative effect on the perceived ease of use and perceived ubiquity. The perceived ubiquity construct affects both user groups' perceived ease of use and perceived usefulness of wearing smart clothes. Most relationships among the original constructs of the TAM were validated in older adults in general. Interestingly, we found that perceived usefulness had an indirect effect on behavioral intention through attitude. These results further confirm the validity of the extended TAM in determining older users' technology acceptance behavior.


Assuntos
Ansiedade/psicologia , Doenças Cardiovasculares/diagnóstico , Modelos Psicológicos , Aceitação pelo Paciente de Cuidados de Saúde/psicologia , Dispositivos Eletrônicos Vestíveis/psicologia , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Ansiedade/etiologia , Tecnologia Biomédica , Feminino , Humanos , Intenção , Masculino , Pessoa de Meia-Idade , Monitorização Ambulatorial/instrumentação , Monitorização Ambulatorial/psicologia , Aceitação pelo Paciente de Cuidados de Saúde/estatística & dados numéricos , Preferência do Paciente , Taiwan , Telemedicina/instrumentação , Telemedicina/estatística & dados numéricos , Tecnologia sem Fio/instrumentação
11.
Orthopedics ; 31(1): 72, 2008 01.
Artigo em Inglês | MEDLINE | ID: mdl-19292166

RESUMO

Proximal femoral deformities can occur in children as sequelae of several disorders such as hip joint infection or avascular necrosis of the femoral head. Early surgical correction of deformities promises a good result; however, limited exposure of the surgical field often creates difficulties for surgeons. Application of a rapid prototyping model for proximal femoral corrective osteotomy in children serves not only as a guide for surgical planning but also as a communication tool between physicians and patients.


Assuntos
Necrose da Cabeça do Fêmur/cirurgia , Cabeça do Fêmur/cirurgia , Prótese de Quadril , Imageamento por Ressonância Magnética/métodos , Osteotomia/instrumentação , Procedimentos de Cirurgia Plástica/instrumentação , Ajuste de Prótese/métodos , Cirurgia Assistida por Computador/instrumentação , Pré-Escolar , Cabeça do Fêmur/patologia , Necrose da Cabeça do Fêmur/patologia , Humanos , Interpretação de Imagem Assistida por Computador/métodos , Masculino , Modelos Anatômicos , Osteotomia/métodos , Procedimentos de Cirurgia Plástica/métodos , Cirurgia Assistida por Computador/métodos , Resultado do Tratamento
12.
Micromachines (Basel) ; 9(9)2018 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-30424383

RESUMO

This study condenses huge amount of raw data measured from a MEMS accelerometer-based, wrist-worn device on different levels of physical activities (PAs) for subjects wearing the device 24 h a day continuously. In this study, we have employed the device to build up assessment models for quantifying activities, to develop an algorithm for sleep duration detection and to assess the regularity of activity of daily living (ADL) quantitatively. A new parameter, the activity index (AI), has been proposed to represent the quantity of activities and can be used to categorize different PAs into 5 levels, namely, rest/sleep, sedentary, light, moderate, and vigorous activity states. Another new parameter, the regularity index (RI), was calculated to represent the degree of regularity for ADL. The methods proposed in this study have been used to monitor a subject's daily PA status and to access sleep quality, along with the quantitative assessment of the regularity of activity of daily living (ADL) with the 24-h continuously recorded data over several months to develop activity-based evaluation models for different medical-care applications. This work provides simple models for activity monitoring based on the accelerometer-based, wrist-worn device without trying to identify the details of types of activity and that are suitable for further applications combined with cloud computing services.

13.
IEEE J Biomed Health Inform ; 22(2): 442-449, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-28113792

RESUMO

Seismocardiogram (SCG) or mechanocardiography is a noninvasive cardiac diagnostic method; however, previous studies used only a single sensor to detect cardiac mechanical activities that will not be able to identify location-specific feature points in a cardiac cycle corresponding to the four valvular auscultation locations. In this study, a multichannel SCG spectrum measurement system was proposed and examined for cardiac activity monitoring to overcome problems like, position dependency, time delay, and signal attenuation, occurring in traditional single-channel SCG systems. ECG and multichannel SCG signals were simultaneously recorded in 25 healthy subjects. Cardiac echocardiography was conducted at the same time. SCG traces were analyzed and compared with echocardiographic images for feature point identification. Fifteen feature points were identified in the corresponding SCG traces. Among them, six feature points, including left ventricular lateral wall contraction peak velocity, septal wall contraction peak velocity, transaortic peak flow, transpulmonary peak flow, transmitral ventricular relaxation flow, and transmitral atrial contraction flow were identified. These new feature points were not observed in previous studies because the single-channel SCG could not detect the location-specific signals from other locations due to time delay and signal attenuation. As the results, the multichannel SCG spectrum measurement system can record the corresponding cardiac mechanical activities with location-specific SCG signals and six new feature points were identified with the system. This new modality may help clinical diagnoses of valvular heart diseases and heart failure in the future.


Assuntos
Insuficiência Cardíaca/fisiopatologia , Testes de Função Cardíaca/métodos , Coração/fisiologia , Processamento de Sinais Assistido por Computador , Acelerometria , Adulto , Feminino , Insuficiência Cardíaca/diagnóstico , Humanos , Masculino , Adulto Jovem
14.
Prosthet Orthot Int ; 31(4): 342-52, 2007 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18050006

RESUMO

Sub-sensory electrical or mechanical stimulation can enhance the sensitivity of the human somatosensory system to improve the balance control capabilities of elderly. In addition, clinical studies suggest that visual-auditory biofeedback can improve sensory compensation for the elderly. This study hypothesizes that the static balance and gait performance of single leg quiet standing and treadmill walking could be improved for providing proprioceptive neuromuscular facilitation using sub-sensory stimulation and visual-auditory biofeedback in amputee subjects. To test this, a computerized foot pressure biofeedback sensory compensation system using sub-threshold low-level electrical stimulation combined with visual-auditory biofeedback was developed. Seven unilateral trans-tibial amputees who wore prostheses over 2 years were recruited. The subjects performed multiple single leg quiet standing trials with sub-sensory electrical stimulation applied at the quadriceps muscle during half of the trials. Static balance performance was characterized by using a Zebris motion analysis system to measure the sway distance and duration of the centre of mass on the second sacral (S2) of the subjects. In addition, multiple treadmill ambulatory trials with or without visual-auditory biofeedback was performed. Dynamic gait performance was characterized with a Zebris instrumented insole to measure the temporal responses of foot pressure sensors. Experimental results showed an improvement in three balance performance indices (Holding Time Index, HTI, Maximum Sway Distance Index, MSDI, and Average Sway Distance Index, ASDI) during single leg quiet standing by applying sub-sensory stimulation. The improvement ratio of these balance performance indices across subjects for single leg quiet standing tests resulted in 132.34% in HTI, 44.61% in MSDI, and 61.45% in ASDI. With visual-auditory biofeedback as a cue for heel contact and toe push-off condition during treadmill ambulation, the improvement of four dynamic gait performance measures (Double Support Period, DSP, Constant Time Cadence, CTC, Single Support Period, SSP, and Stance/Swing Ratio, SSR) in amputees was verified. This resulted in 7.89% in DSP (affected side), 5.09% in CTC, 16.67% in SSP (sound side), 45.30% in SSR (sound side), and 40.30% in SSR (affected side) respectively. These findings suggest that sub-threshold electrical stimulation and visual-auditory biofeedback rehabilitation strategies may be effective in compensating sensory loss and improving static balance and dynamic ambulation performance for amputees.


Assuntos
Amputação Cirúrgica/reabilitação , Biorretroalimentação Psicológica , Terapia por Estimulação Elétrica/métodos , Transtornos Neurológicos da Marcha/reabilitação , Equilíbrio Postural , Transtornos de Sensação/reabilitação , Estimulação Acústica , Adulto , Feminino , Transtornos Neurológicos da Marcha/etiologia , Humanos , Masculino , Pessoa de Meia-Idade , Transtornos de Sensação/etiologia
15.
J Healthc Eng ; 2017: 4728187, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29065608

RESUMO

Overnight polysomnography (PSG) is currently the standard diagnostic procedure for obstructive sleep apnea (OSA). It has been known that monitoring of head position in sleep is crucial not only for the diagnosis (positional sleep apnea) but also for the management of OSA (positional therapy). However, there are no sensor systems available clinically to hook up with PSG for accurate head position monitoring. In this paper, an accelerometer-based sensing system for accurate head position monitoring is developed and realized. The core CORDIC- (COordinate Rotation DIgital Computer-) based tilting sensing algorithm is realized in the system to quickly and accurately convert accelerometer raw data into the desired head position tilting angles. The system can hook up with PSG devices for diagnosis to have head position information integrated with other PSG-monitored signals. It has been applied in an IRB test in Taipei Veterans General Hospital and has been proved that it can meet the medical needs of accurate head position monitoring for PSG diagnosis.


Assuntos
Cabeça/fisiologia , Polissonografia/instrumentação , Apneia Obstrutiva do Sono/diagnóstico , Decúbito Dorsal/fisiologia , Acelerometria , Humanos
16.
J Tissue Eng Regen Med ; 10(10): E337-E353, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-23955935

RESUMO

The current study aimed to fabricate three-dimensional (3D) polycaprolactone (PCL), polycaprolactone and ß-tricalcium phosphate (PCL-TCP) scaffolds via a selective laser-sintering technique (SLS). Collagen type I was further coated onto PCL-TCP scaffolds to form PCL-TCP-COL scaffolds. The physical characters of these three scaffolds were analysed. The osteogenic potential of porcine adipose-derived stem cells (pASCs) was compared among these three scaffolds in order to find an optimal scaffold for bone tissue engineering. The experimental results showed no significant differences in pore size and porosity among the three scaffolds; the porosity was ca. 75-77% and the pore size was ca. 300-500 µm in all three. The compressive modulus was increased from 6.77 ± 0.19 to 13.66 ± 0.19 MPa by adding 30% ß-TCP into a 70% PCL scaffold. No significant increase of mechanical strength was found by surface-coating with collagen type I. Hydrophilicity and swelling ratios showed statistical elevation (p < 0.05) after collagen type I was coated onto the PCL-TCP scaffolds. The in vitro study demonstrated that pASCs had the best osteogenic differentiation on PCL-TCP-COL group scaffolds, due to the highest ALP activity, osteocalcin mRNA expression and mineralization. A nude mice experiment showed better woven bone and vascular tissue formation in the PCL-TCP-COL group than in the PCL group. In conclusion, the study demonstrated the ability to fabricate 3D, porous PCL-TCP composite scaffolds (PCL:TCP = 70:30 by weight) via an in-house-built SLS technique. In addition, the osteogenic ability of pASCs was found to be enhanced by coating COL onto the PCL-TCP scaffolds, both in vitro and in vivo. Copyright © 2013 John Wiley & Sons, Ltd.


Assuntos
Tecido Adiposo/metabolismo , Fosfatos de Cálcio/química , Materiais Revestidos Biocompatíveis/química , Colágeno Tipo I/química , Osteogênese , Poliésteres/química , Células-Tronco/metabolismo , Alicerces Teciduais/química , Tecido Adiposo/citologia , Animais , Lasers , Células-Tronco/citologia , Suínos
17.
Biofabrication ; 6(1): 015004, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24429581

RESUMO

Selective laser sintering (SLS), an additive manufacturing (AM) technology, can be used to produce tissue engineering scaffolds with pre-designed macro and micro features based on computer-aided design models. An in-house SLS machine was built and 3D poly-ε-caprolactone (PCL) scaffolds were manufactured using a layer-by-layer design of scaffold struts with varying orientations (0°/45°/0°/45°, 0°/90°/0°/90°, 0°/45°/90°/135°), producing scaffolds with pores of different shapes and distribution. To better enhance the scaffold properties, chondrocytes were seeded in collagen gel and loaded in scaffolds for cartilage tissue engineering. Gel uptake and dynamic mechanical analysis demonstrated the better suitability of the 0°/90°/0°/90° scaffolds for reconstructive cartilage tissue engineering purposes. Chondrocytes were then seeded onto the 0°/90°/0°/90° scaffolds in collagen I hydrogel (PCL/COL1) and compared to medium-suspended cells in terms of their cartilage-like tissue engineering parameters. PCL/COL1 allowed better cell proliferation when compared to PCL or two-dimensional tissue culture polystyrene. Scanning electron microscopy and confocal microscopy observations demonstrated a similar trend for extracellular matrix production and cell survival. Glycosaminoglycan and collagen II quantification also demonstrated the superior matrix secretion properties of PCL/COL1 hybrid scaffolds. Collagen-gel-suspended chondrocytes loaded in SLS-manufactured PCL scaffolds may provide a means of producing tissue-engineered cartilage with customized shapes and designs via AM technology.


Assuntos
Cartilagem/crescimento & desenvolvimento , Colágeno/química , Hidrogel de Polietilenoglicol-Dimetacrilato/química , Poliésteres/química , Engenharia Tecidual/métodos , Alicerces Teciduais/química , Implantes Absorvíveis , Animais , Materiais Biocompatíveis/química , Cartilagem/citologia , Proliferação de Células , Células Cultivadas , Condrócitos/citologia , Masculino , Camundongos , Camundongos Nus , Suínos , Engenharia Tecidual/instrumentação
18.
J Lab Autom ; 19(1): 91-9, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23603751

RESUMO

Conventional methods to prepare sperm have been amenable to the investigation of outcomes such as rates of recovery and conventional semen parameters. The standard preparation of sperm for assisted reproduction is criticized for its centrifugation steps, which might either recover motile sperm in variable proportions or increase the probability of damage to sperm DNA. An microfluidic system was designed to separate motile sperm according to a design whereby nonmotile spermatozoa and debris flow along their initial streamlines and exit through one outlet-up, whereas motile spermatozoa have an opportunity to swim into a parallel stream and to exit through a separate outlet-down. This chip was fabricated by microelectromechanical systems technology with polydimethylsiloxane molding. The hydrophilic surface, coated with poly (ethanediol) methyl ether methacrylate, exhibits enduring stability maintained for the microchannel. Microscopic examination and fluorescent images showed that the motility of sperm varied with the laminar streams. To confirm the sorting, we identified and quantified the proportions of live and dead sperm before and after sorting with flow cytometric analysis. The results on the viability of a sample demonstrated the increased quality of sperm after sorting and collection in the outlet reservoir. The counted ratio of live sperm revealed the quantity and efficiency of the sorted sperm.


Assuntos
Separação Celular/métodos , Técnicas Analíticas Microfluídicas/métodos , Espermatozoides/fisiologia , Animais , Masculino , Camundongos Endogâmicos ICR , Motilidade dos Espermatozoides
19.
Mater Sci Eng C Mater Biol Appl ; 40: 389-97, 2014 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-24857507

RESUMO

Surface modified porous polycaprolactone scaffolds fabricated via rapid prototyping techniques were evaluated for cartilage tissue engineering purposes. Polycaprolactone scaffolds manufactured by selective laser sintering (SLS) were surface modified through immersion coating with either gelatin or collagen. Three groups of scaffolds were created and compared for both mechanical and biological properties. Surface modification with collagen or gelatin improved the hydrophilicity, water uptake and mechanical strength of the pristine scaffold. From microscopic observations and biochemical analysis, collagen-modified scaffold was the best for cartilage tissue engineering in terms of cell proliferation and extracellular matrix production. Chondrocytes/collagen-modified scaffold constructs were implanted subdermally in the dorsal spaces of female nude mice. Histological and immunohistochemical staining of the retrieved implants after 8 weeks revealed enhanced cartilage tissue formation. We conclude that collagen surface modification through immersion coating on SLS-manufactured scaffolds is a feasible scaffold for cartilage tissue engineering in craniofacial reconstruction.


Assuntos
Cartilagem/metabolismo , Lasers , Poliésteres/química , Engenharia Tecidual , Animais , Substitutos Ósseos/química , Substitutos Ósseos/farmacologia , Cartilagem/citologia , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Condrócitos/citologia , Colágeno/química , Colágeno/metabolismo , Matriz Extracelular/metabolismo , Feminino , Camundongos , Camundongos Nus , Porosidade , Regeneração/efeitos dos fármacos , Propriedades de Superfície , Suínos , Alicerces Teciduais
20.
Materials (Basel) ; 6(11): 4911-4929, 2013 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-28788367

RESUMO

Three-dimensional porous polycaprolactone (PCL) scaffolds with consistent inter-pore channels, 83% porosity and 300-400 µm pore size were fabricated via selective laser sintering. The PCL scaffold was combined with platelet-rich plasma (PRP) to form a bioactive composite and studied for potential application in bone tissue engineering using porcine adipose-derived stem cells (PASCs). The PCL/PRP/PASCs construct showed enhanced cell seeding efficiency and synergistically increased the differentiation capability of PASCs in osteogenic medium toward the osteoblast lineage, judging from elevated alkaline phosphatase activity and up-regulated osteogenic genes expression. For in vivo study, a 3 cm × 3 cm mandible defect was created in pigs and reconstructed by implanting acellular PCL scaffolds or PCL/PRP/PASCs constructs. Both groups showed new bone formation, however, the new bone volume was 5.1 times higher for PCL/PRP/PASCs 6 months post-operation. The bone density was less and loose in the acellular PCL group and the Young's modulus was only 29% of normal bone. In contrast, continued and compact bone formation was found in PCL/PRP/PASCs and the Young's modulus was 81% that of normal bone. Masson's trichrome stain, immunohistochemical analysis of osteocalcin and collagen type I also confirmed new bone formation.

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