Impacts of climate change-induced natural hazards on women and their human rights implications: A study in the southwest coast of Bangladesh.

Women in coastal areas are particularly vulnerable to climate change impacts due to existing gender inequality and socio-cultural norms in Bangladesh. This research aims to explore the vulnerability of women to climate change-induced natural hazards, the challenges they face due to the chain impacts of climate change, and the resulting violation of women's rights. Quantitative and qualitative data were used in this study, where 260 structured questionnaire surveys and 15 Focus Group Discussions were performed at Mongla and Shyamnagar Upazilas in Bagerhat and Satkhira districts, respectively. The quantitative data were analyzed using SPSS 26.0 software, and qualitative data was analyzed thematically. The results disclose that most respondents in Mongla and Shyamnagar reported an increase in the occurrence rate of climate change-induced natural hazards, with cyclones, salinity, and riverbank erosion being the most devastating in Mongla and cyclones, salinity, and storm surges in Shyamnagar. It affects the lives and livelihoods of people, with women being particularly vulnerable due to limited access to education, healthcare, and economic opportunities, and women's rights are violated in these areas. Half of the study area's population has been suffering from infections or inflammation in reproductive organs, especially among fisherwomen. The findings of this study recommend that provisions for alternative livelihoods should be made for women, and all women must be brought under the umbrella of fair social safety net programs.

Biological Properties and Biomedical Applications of Pectin and Pectin-Based Composites: A Review.

Pectin has recently drawn much attention in biomedical applications due to its distinctive chemical and biological properties. Polymers like pectin with cell-instructive properties are attractive natural biomaterials for tissue repair and regeneration. In addition, bioactive pectin and pectin-based composites exhibit improved characteristics to deliver active molecules. Pectin and pectin-based composites serve as interactive matrices or scaffolds by stimulating cell adhesion and cell proliferation and enhancing tissue remodeling by forming an extracellular matrix in vivo. Several bioactive properties, such as immunoregulatory, antibacterial, anti-inflammatory, anti-tumor, and antioxidant activities, contribute to the pectin's and pectin-based composite's enhanced applications in tissue engineering and drug delivery systems. Tissue engineering scaffolds containing pectin and pectin-based conjugates or composites demonstrate essential features such as nontoxicity, tunable mechanical properties, biodegradability, and suitable surface properties. The design and fabrication of pectic composites are versatile for tissue engineering and drug delivery applications. This article reviews the promising characteristics of pectin or pectic polysaccharides and pectin-based composites and highlights their potential biomedical applications, focusing on drug delivery and tissue engineering.

Satisfying QTPP of Erythropoietin Biosimilar by QbD through DoE-Derived Downstream Process Engineering.

Well-characterized and scalable downstream processes for the purification of biologics are extremely demanding for delivering quality therapeutics to patients at a reasonable price. Erythropoietin (EPO) is a blockbuster biologic with diverse clinical applications, but its application is limited to financially well-off societies due to its high price. The high price of EPO is associated with the technical difficulties related to the purification challenge to obtain qualified products with a cost-effective defined process. Though there are reports for the purification of EPO there is no report of a well-characterized downstream process with critical process parameters (CPPs) that can deliver EPO consistently satisfying the quality target product profile (QTPP), which is a critical regulatory requirement. To advance the field, we applied the quality by design (QbD) principle and design of experiment (DoE) protocol to establish an effective process, which is scalable up to 100× batch size satisfying QTPP. We have successfully transformed the process from static mode to dynamic mode and validated it. Insignificant variation (p > 0.05) within and between 1×, 10×, and 100× batches showed that the process is reproducible and seamlessly scalable. The biochemical analysis along with the biofunctionality data ensures that the products from different scale batches were indifferent and comparable to a reference product. Our study thereby established a robust and scalable downstream process of EPO biosimilar satisfying QTPP. The technological scheme presented here can speed up the production of not only EPO but also many other life-saving biologics and make them available to the mass population at a reduced cost.

Biowastes of slaughterhouses and wet markets: an overview of waste management for disease prevention.

Slaughterhouse and wet market wastes are pollutants that have been always neglected by society. According to the Food and Agriculture Organization of the United Nations, more than three billion and nineteen million livestock were consumed worldwide in 2018, which reflects the vast amount and the broad spectrum of the biowastes generated. Slaughterhouse biowastes are a significant volume of biohazards that poses a high risk of contamination to the environment, an outbreak of diseases, and insecure food safety. This work comprehensively reviewed existing biowaste disposal practices and revealed the limitations of technological advancements to eradicate the threat of possible harmful infectious agents from these wastes. Policies, including strict supervision and uniform minimum hygienic regulations at all raw food processing factories, should therefore be tightened to ensure the protection of the food supply. The vast quantity of biowastes also offers a zero-waste potential for a circular economy, but the incorporation of biowaste recycling, including composting, anaerobic digestion, and thermal treatment, nevertheless remains challenging.

Suicide in Bangla Movie and Drama: A Content Analysis.

We aimed to assess how suicidality has been depicted in Bangla movies and dramas. We conducted a search on YouTube by using search terms to identify movies and dramas with suicidal scripts. The search was performed between February and May 2022 resulting in 71 items consisting of 35 Bangla movies and 36 Bangla dramas. We scrutinized the contents of movies and dramas against our pre-designed instrument and we assessed their quality against World Health Organization guidelines. Among the 71 suicidal behaviors, 46.5% were suicides, 72% of the suicidal behavior was noted in young adults, 63.9% were unmarried, and 69% attempts were found in prominent characters. Hanging was found as the most prominent method (25.4%) and premarital and extramarital affairs and sexual harassment were the most prominent risk factors (60.6%). The potentially harmful characteristics were present in almost all events whereas potentially helpful contents were mentioned very minimally.

Job insecurity and mental health related outcomes among the humanitarian workers during COVID-19 pandemic: a cross-sectional study.

BACKGROUND: The COVID-19 remains a public health burden that has caused global economic crises, jeopardizing health, jobs, and livelihoods of millions of people around the globe. Several efforts have been made by several countries by implementing several health strategies to attenuate the spread of the pandemic. Although several studies indicated effects of COVID-19 on mental health and its associated factors, very little is known about the underlying mechanism of job insecurity, depression, anxiety, and stress in Bangladesh. Therefore, this study determined the prevalence of job insecurity and depression, anxiety, stress as well as the association between job insecurity, mental health outcomes also contributing determinants amongst humanitarian workers during the COVID-19 pandemic in Bangladesh. METHODS: We conducted a web-based cross-sectional study among 445 humanitarian workers during the COVID-19 pandemic in six sub-districts of Cox's bazar district of Bangladesh between April and May 2021. The questionnaire was composed of socio-demographic, lifestyle and work related factors. Psychometric instruments like job insecurity scale and depression, anxiety also stress scale (DASS-21) were employed to assess the level of job insecurity and mental health outcomes (depression, anxiety and stress). STATA software version 14 was employed to perform statistical analyses. RESULTS: The prevalence of job insecurity was 42%. The odds of job insecurity was higher in Kutubdia and Pekua (AOR = 3.1, 95% CI 1.36, 7.22) Teknaf (AOR = 2.9, 95% CI 1.33, 6.41), the impact of dissatisfaction on salary (AOR = 2.3, 95% CI 1.49, 3.58) was evident with job insecurity. The prevalence of moderate to severe depression, anxiety and stress among humanitarian worker were (26%, 7%), (25%, 10%) and (15%, 7%) respectively. Further, the region of work, being female, marital status, work environment, and salary dissatisfaction were contributing factors for poor mental health outcomes. Those with job insecurity were almost 3 times more likely to experience depression (AOR = 2.7, 95% CI 1.85, 4.04), anxiety (AOR = 2.6, 95% CI 1.76, 3.71) and stress (AOR: 2.8; 95% CI 1.89, 4.26), respectively. CONCLUSION: Our findings highlight that job security remains essential to help tackle the severity of depression, anxiety and stress in humanitarian workers. The results reflected the critical importance of local and international NGOs addressing poor mental health conditions of their employees to prevent mental health outbreaks.

The impact of the COVID-19 pandemic on lifestyle patterns: Does gender matter?

Background: The COVID-19 pandemic has significantly impacted individuals to deviate from normal lifestyle behaviors. But, there is a paucity of studies conducted in Bangladesh assessing how lifestyle patterns (i.e., smoking, drug use, physical exercise) have changed after the pandemic, which was investigated in this study. Methods: An online-based cross-sectional survey was conducted among a total of 756 Bangladeshi young adults between April 1 and 13, 2020. Lifestyle patterns data were collected based on two periods from the COVID-19 pandemic inception point in the country, (i) '1 year before', and (ii) '1 year after'. Basic descriptive statistics (i.e., frequency and percentages) and Chi-square tests were performed to examine the associations of the independent variables in relation to lifestyle patterns. Results: A 0.2 and 4.7% reduction in smoking and physical exercise, respectively, was observed after the pandemic. But the prevalence of drug use was 1.5% before the COVID-19 pandemic, which rose to 1.9% during the pandemic; representing a 0.4% increment. The changes in lifestyle patterns before and during the COVID-19 pandemic was statistically significant only for physical exercise. Of the gender, male participants were more prevalent in smoking, drug use, and performing physical exercise in both periods. Conclusion: It is suggested to increase awareness concerning adverse effects of drug use and not performing physical exercise, where the gender-based focus is highly appreciated.

Factors associated with depression and determining dimensions of job satisfaction among physicians in Bangladesh.

Background: Depression in physicians emerges early in their academic and professional careers. Lengthy and irregular duty time, high levels of obligation, job dissatisfaction, workstation culture, organizational rules, and so on significantly increased the psychological pressure on physicians. Objectives: The study's aim was to measure the level of depression, association, and influence of socio-demographic characteristics and job satisfaction on depression among physicians in Bangladesh, as well as to explore the factor structure of job satisfaction measure and examine its internal reliability. Methods: Data were collected using a self-administered questionnaire in a cross-sectional survey of 301 physicians. The factors related to depression were investigated using a multivariable logistic regression model, and factor analysis was done to identify the important factors associated with job satisfaction. Results: Male respondents made up 49.5 percent of the sample overall, while female respondents made up 50.5 percent. 24.58% of the physicians had mild depression, whereas 13.29%, 7.31%, and 0.66% of the participants had moderate, moderately severe, and severe depression, respectively. In multivariable analysis, sex (male vs. female, AOR: 2.16, 95% CI:1.28-3.62), monthly income <15000 BDT vs. >40000 BDT, (AOR: 0.35, 95% CI: 0.14-0.89), and income <15000 BDT vs. 15,000-24,999 BDT (AOR: 0.36, 95% CI: 0.15-0.89) were the essential factors associated with depression. Furthermore, with each unit increase in the job satisfaction score was related to a 71% decrease in the odds of physicians having depression. Conclusion: The findings of this study indicate that providing appropriate organizational support, proper work assignments, and an adequate opportunity to develop their professional skills and career irrespective of sex may increase overall job satisfaction. Ultimately, this will serve to improve patient care as well as the whole health system's output.

Psychometric Properties of the Short-Form Geriatric Depression Scale (GDS-SF) and Its Associated Factors among the Elderly in Bangladesh.

Background: This study aimed to (1) evaluate the psychometric properties of a Comprehensive Short-Form Geriatric Depression Scale (GDS-SF) and (2) examine the associated factors of GDS-SF among the elderly. Methods: A cross-sectional study was conducted from November 2019 to April 2020 in Dhaka City Corporation, Bangladesh. Data of 377 elderly were collected, including socio-demographic characteristics, social supports, comorbidities, sleep behaviours, and depression (as measured by the GDS-SF). We used the principal component analysis, correlation analysis, and logistic regression analysis to validate GDS-SF, and explore its associations. Results: The GDS-SF was reliable and homogeneous with Cronbach's alpha = 0.836, and McDonald's Omega = 0.841, with no floor/ceiling effects. The questionnaire demonstrated a good construct validity with item-scale convergent validity and KMO measure of sampling adequacy (0.869 for the total sample, 0.838 for the community subsample, and 0.851 for the slum subsample). In the multivariate model, older people had a higher likelihood of moderate and severe depression (OR, 1.06; 95% CI, 1.00, 1.12; p = 0.048). The likelihood of having moderate and severe depression was lower in men (OR, 0.48; 95% CI, 0.28, 0.85; p = 0.011) and those satisfied with their children's support (OR, 0.17; 95% CI, 0.08, 0.35; p < 0.001), compared with their counterparts, respectively. Conclusions: The GDS-SF is a reliable and valid survey tool for evaluating depression in Bangladeshi older adults. Age, gender, and satisfaction with children's support were predictors of depression.

DoE-derived continuous and robust process for manufacturing of pharmaceutical-grade wide-range LNPs for RNA-vaccine/drug delivery.

Lipid nanoparticle (LNP) technology has become extremely demanding for delivering RNA-products and other drugs. However, there is no platform to manufacture pharmaceutical-grade LNPs with desired particle size from a wide range in continuous mode. We have developed a unique platform to obtain any specific size-range of LNPs from 60 to 180 nm satisfying pharmaceutical regulatory requirements for polydispersity index, sterility, dose uniformity and bio-functionality. We applied design of experiment (DoE) methodology and identified the critical process parameters to establish the process for global application. Cross-point validation within the response map of DoE confirmed that the platform is robust to produce specific size (± 10 nm) of LNPs within the design-range. The technology is successfully transformed to production scale and validated. Products from R&D, pilot and production batches for a candidate SARS-CoV-2 mRNA-vaccine generated equivalent biological responses. The data collectively established the robustness and bio-uniformity of doses for global RNA-vaccine/drug formulation.

Arsenic, iron, and manganese in groundwater and its associated human health risk assessment in the rural area of Jashore, Bangladesh.

This study investigated groundwater pollution and potential human health risks from arsenic, iron, and manganese in the rural area of Jashore, Bangladesh. Study results show that the mean value of groundwater pH is 7.25 ± 0.31, with a mean conductivity of 633.94 ± 327.41 µs/cm, while about 73, 97, and 91% of groundwater samples exceeded the Bangladesh drinking water standard limits for As, Fe, and Mn, respectively. Groundwater pollution evaluation indices, including the heavy metal pollution index, the heavy metal evaluation index, the degree of contamination, and the Nemerow pollution index, show that approximately 97, 82, 100, and 100% of samples are in the high degree of pollution category, respectively. Spatial distribution exhibited that the study area is highly exposed to As (73%), Fe (82%), and Mn (46%). In the case of non-carcinogenic health risk via oral exposure, about 94% of samples suggest a high category of risk for infants, and 97% of samples are found to be at high risk for children and adults. The carcinogenic risk of arsenic via an oral exposure pathway suggests that approximately 97% of the samples are found to be at high risk for infants, and all of the samples are at high risk for both adults and children.

A review on the contamination of SARS-CoV-2 in water bodies: Transmission route, virus recovery and recent biosensor detection techniques.

The discovery of SARS-CoV-2 virus in the water bodies has been reported, and the risk of virus transmission to human via the water route due to poor wastewater management cannot be disregarded. The main source of the virus in water bodies is the sewage network systems which connects to the surface water. Wastewater-based epidemiology has been applied as an early surveillance tool to sense SARS-CoV-2 virus in the sewage network. This review discussed possible transmission routes of the SARS-CoV-2 virus and the challenges of the existing method in detecting the virus in wastewater. One significant challenge for the detection of the virus is that the high virus loading is diluted by the sheer volume of the wastewater. Hence, virus preconcentration from water samples prior to the application of virus assay is essential to accurately detect traceable virus loading. The preparation time, materials and conditions, virus type, recovery percentage, and various virus recovery techniques are comprehensively discussed in this review. The practicability of molecular methods such as Polymer-Chain-Reaction (PCR) for the detection of SARS-CoV-2 in wastewater will be revealed. The conventional virus detection techniques have several shortcomings and the potential of biosensors as an alternative is also considered. Biosensing techniques have also been proposed as an alternative to PCR and have reported detection limits of 10 pg/µl. This review serves to guide the reader on the future designs and development of highly sensitive, robust and, cost effective SARS-CoV-2 lab-on-a-chip biosensors for use in complex wastewater.

Sleep Problems in Children with Autism Spectrum Disorder in Bangladesh: A Case-Control Study.

BACKGROUND: Sleep problems in children with Autism Spectrum Disorder (ASD) are highly prevalent, but little information is available on this issue in low- to middle-income countries (LMIC) such as Bangladesh. Therefore, the present study investigated the prevalence and socio-demographic determinants of ASD sleep disturbances in a comparison with typically developing children (TDC). METHODS: A cross-sectional interview study was carried out within a total of 446 Bangladeshi mothers, whose children's mean age was 8.1±2.9 years (151 ASD [8.5±2.7 years] and 295 TDC [7.9±2.9 years]); in addition to socio-demographics, the Child Sleep Habit Questionnaire (CSHQ) was used, and a cut-off score of 41 out of 93 points considered as reflecting sleep problems. RESULTS: About 89.7% of the children reported having problems in sleep, with ASD reporting higher frequency vs TDC (94.00% vs 87.50%; χ2=4.678, p=0.031). The overall mean CSHQ score was 48.7±7.6 in total sample, whereas ASD children reported higher scores compared to TDCs (50.9±8.1 vs 47.5±7.0, p<0.001). Similarly, subscales of CSHQ such as sleep duration (4.23±1.56 vs 3.90±1.31, p=0.017), sleep anxiety (7.23±2.05 vs 6.45±1.92, p<0.001), night waking (3.82±1.07 vs 3.17±1.89, p<0.001), parasomnias (8.86±2.06 vs 7.85±2.27, p<0.001), and sleep disordered breathing (4.02±2.92 vs 3.43±2.07, p=0.014) were more problematic among ASD compared to TDC. Lastly, 28.5% of ASD reported taking sleep-related medications vs 0.3% for TDC (n=1). CONCLUSION: Bangladeshi ASD children are highly likely to manifest sleep disturbances, which warrant urgent implementation of parental educational and support programs to mitigate the impact of sleep problems in ASD families.

An mRNA-based vaccine candidate against SARS-CoV-2 elicits stable immuno-response with single dose.

D614G genotype of SARS-CoV-2 virus is highly infectious and responsible for almost all infection for 2nd wave. However, there are currently no reports with D614G as vaccine candidate. Here we report the development of an mRNA-LNP vaccine with D614G variant and characterization in animal model. We have used special mRNA-architecture and formulation that provides suitable response of the product. The surface plasmon resonance (SPR) data with spike protein (S) revealed that immunization generated specific antibody pools against the whole extracellular domain (RBD and S2) of the spike protein. The anti-sera and purified IgGs from immunized mice neutralized SARS-CoV-2-pseudoviruses in ACE2-expressing HEK293 cells in a dose dependent manner. Importantly, single-dose immunization protected mice-lungs from homotypic-pseudovirus entry and cytopathy. The immunologic responses have been implicated by a balanced and stable population of CD4+ cells with a Th1 bias. The data suggested great promise for immediate translation of the technology to the clinic.

Psychological and Livelihood Impacts of COVID-19 on Bangladeshi Lower Income People.

The objective of this research is to understand the psychological and livelihood-related impacts of coronavirus disease 2019 (COVID-19) on Bangladeshi lower income group people who depend on daily earnings for their living. Following the convenience sampling method, 576 respondents were interviewed for quantitative data and 30 in-depth interviews for qualitative information in several districts of Bangladesh. To 94.1% respondents, livelihood has been affected by the COVID-19 outbreak with an overall score of 3.20 ± 0.77 on a 4-point Likert-type scale. In comparison to unemployed respondents, daily workers have been hardly affected by the COVID-19 outbreak (odds ratio [OR] = 7.957; P < .01), and so they are going outside more frequently in search of jobs (OR = 9.984, P < .01). Due to fear of COVID-19 infection and lack of livelihood means, respondents (76.6%) have been stressed out (overall score 3.19 ± 0.81 on a 4-point Likert-type scale), and those working in industries (OR = 5.818, P < .01), farmers (OR = 3.029, P < .05), and day laborers (OR = 2.651, P < .05) have been highly stressed.

A novel knowledge-derived data potentizing method revealed unique liver cancer-associated genetic variants.

BACKGROUND: Next-generation sequencing (NGS) has been advancing the progress of detection of disease-associated genetic variants and genome-wide profiling of expressed sequences over the past decade. NGS enables the analyses of multiple regions of a genome in a single reaction format and has been shown to be a cost-effective and efficient tool for root-cause analysis of disease and optimization of treatment. NGS has been leading global efforts to device personalized and precision medicine (PM) in clinical practice. The effectiveness of NGS for the aforementioned applications has been proven unequivocal for multifactorial diseases like cancer. However, definitive prediction of cancer markers for all types of diseases and for global populations still remains highly rewarding because of the diversity of cancer types and genetic variants in human. RESULTS: We performed exome sequencing of four samples in quest of critical genetic factor/s associated with liver cancer. By imposing knowledge-based filter chains, we have revealed a panel of genetic variants, which are unrecognized by current major genomics data repositories. Total 20 MNV-induced, 5 INDEL-induced, and 31 SNV-induced neoplasm-exclusive genes were revealed through NGS data acquisition followed by data curing with the application of quality filter chains. Liver-specific expression profile of the identified gene pool is directed to the selection of 17 genes which could be the as likely causative genetic factors for liver cancer. Further study on expression level and relevant functional significance enables us to identify and conclude the following four novel variants, viz., c.416T>C (p.Phe139Ser) in SORD, c.1048_1049delGCinsCG (p.Ala350Arg) in KRT6A, c.1159G>T (p.Gly387Cys) in SVEP1, and c.430G>C (p.Gly144Arg) in MRPL38 as a critical genetic factor for liver cancer. CONCLUSION: By applying a novel data prioritizing rationale, we explored a panel of previously unaddressed liver cancer-associated variants. These findings may have an opportunity for early prediction of neoplasm/cancer in liver and designing of relevant personalized/precision liver cancer therapeutics in clinical practice. Since NGS protocol is associated with tons of non-specific mutations due to the variation in background genetic makeup of subjects, therefore, our method of data curing could be applicable for more effective screening of global genetic variants related to disease onset, progression, and remission.

Electrodeposition of Ginseng/Polyaniline Encapsulated Poly(lactic-co-glycolic Acid) Microcapsule Coating on Stainless Steel 316L at Different Deposition Parameters.

Electrodeposition is commonly used to deposit ceramic or metal coating on metallic implants. Its utilization in depositing polymer microcapsule coating is currently being explored. However, there is no encapsulation of drug within polymer microcapsules that will enhance its chemical and biological properties. Therefore, in this study, ginseng which is known for its multiple therapeutic effects was encapsulated inside biodegradable poly(lactic-co-glycolic acid) (PLGA) microcapsules to be coated on pre-treated medical grade stainless steel 316L (SS316L) using an electrodeposition technique. Polyaniline (PANI) was incorporated within the microcapsules to drive the formation of microcapsule coating. The electrodeposition was performed at different current densities (1-3 mA) and different deposition times (20-60 s). The chemical composition, morphology and wettability of the microcapsule coatings were characterized through attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), scanning electron microscopy (SEM) and contact angle analyses. The changes of electrolyte colors, before and after the electrodeposition were also observed. The addition of PANI has formed low wettability and uniform microcapsule coatings at 2 mA current density and 40 s deposition time. Reduction in the current density or deposition time caused less attachment of microcapsule coatings with high wettability records. While prolonging either one parameter has led to debris formation and melted microcapsules with non-uniform wettability measurements. The color of electrolytes was also changed from milky white to dark yellow when the current density and deposition time increased. The application of tolerable current density and deposition time is crucial to obtain a uniform microcapsule coating, projecting a controlled release of encapsulated drug.

Biomineralized Conductive PEDOT: PSS-Coated PLA/PHBV/HA Nanofibrous Membranes.

Conductive materials are potential candidates for developing bone tissue engineering scaffolds as they are nontoxic and can enhance bone tissue regeneration. Their bioactivity can be enhanced by depositing biomineralization in simulated body fluid (SBF). In the current study, a composite electrospun membrane made up of poly(lactic) acid, poly(3-hydroxybutyrate-co-3-hydroxyvalerate), and hydroxyapatite was fabricated using an electrospinning method. The fabricated membranes were dip-coated with a conductive polymer solution, poly(3,4-ethylenedioxythiophene) poly(4-styrenesulfonate), to induce conductivity. Characterization of the membranes based on characteristics such as morphology, chemical bonding, and wettability was conducted using scanning electron microscopy, field emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, attenuated total reflectance Fourier transform infrared spectroscopy, and contact angle measurement. From the results, biomineralization of both coated and noncoated composite membranes was observed on the surface of nanofibers after 21 days in SBF. The membranes provide a superhydrophilic surface as shown by the contact angle. In conclusion, this biomimetic electrospun composite membrane could be used to further support cell growth for bone tissue engineering application.

Comparison of biophysical properties characterized for microtissues cultured using microencapsulation and liquid crystal based 3D cell culture techniques.

Growing three dimensional (3D) cells is an emerging research in tissue engineering. Biophysical properties of the 3D cells regulate the cells growth, drug diffusion dynamics and gene expressions. Scaffold based or scaffoldless techniques for 3D cell cultures are rarely being compared in terms of the physical features of the microtissues produced. The biophysical properties of the microtissues cultured using scaffold based microencapsulation by flicking and scaffoldless liquid crystal (LC) based techniques were characterized. Flicking technique produced high yield and highly reproducible microtissues of keratinocyte cell lines in alginate microcapsules at approximately 350 ± 12 pieces per culture. However, microtissues grown on the LC substrates yielded at lower quantity of 58 ± 21 pieces per culture. The sizes of the microtissues produced using alginate microcapsules and LC substrates were 250 ± 25 µm and 141 ± 70 µm, respectively. In both techniques, cells remodeled into microtissues via different growth phases and showed good integrity of cells in field-emission scanning microscopy (FE-SEM). Microencapsulation packed the cells in alginate scaffolds of polysaccharides with limited spaces for motility. Whereas, LC substrates allowed the cells to migrate and self-stacking into multilayered structures as revealed by the nuclei stainings. The cells cultured using both techniques were found viable based on the live and dead cell stainings. Stained histological sections showed that both techniques produced cell models that closely replicate the intrinsic physiological conditions. Alginate microcapsulation and LC based techniques produced microtissues containing similar bio-macromolecules but they did not alter the main absorption bands of microtissues as revealed by the Fourier transform infrared spectroscopy. Cell growth, structural organization, morphology and surface structures for 3D microtissues cultured using both techniques appeared to be different and might be suitable for different applications.

Characterization, drug loading and antibacterial activity of nanohydroxyapatite/polycaprolactone (nHA/PCL) electrospun membrane.

Considering the important factor of bioactive nanohydoxyapatite (nHA) to enhance osteoconductivity or bone-bonding capacity, nHA was incorporated into an electrospun polycaprolactone (PCL) membrane using electrospinning techniques. The viscosity of the PCL and nHA/PCL with different concentrations of nHA was measured and the morphology of the electrospun membranes was compared using a field emission scanning electron microscopy. The water contact angle of the nanofiber determined the wettability of the membranes of different concentrations. The surface roughness of the electrospun nanofibers fabricated from pure PCL and nHA/PCL was determined and compared using atomic force microscopy. Attenuated total reflectance Fourier transform infrared spectroscopy was used to study the chemical bonding of the composite electrospun nanofibers. Beadless nanofibers were achieved after the incorporation of nHA with a diameter of 200-700 nm. Results showed that the fiber diameter and the surface roughness of electrospun nanofibers were significantly increased after the incorporation of nHA. In contrast, the water contact angle (132° ± 3.5°) was reduced for PCL membrane after addition of 10% (w/w) nHA (112° ± 3.0°). Ultimate tensile strengths of PCL membrane and 10% (w/w) nHA/PCL membrane were 25.02 ± 2.3 and 18.5 ± 4.4 MPa. A model drug tetracycline hydrochloride was successfully loaded in the membrane and the membrane demonstrated good antibacterial effects against the growth of bacteria by showing inhibition zone for E. coli (2.53 ± 0.06 cm) and B. cereus (2.87 ± 0.06 cm).