Agar Concentration Research Articles

Optimizing the radiation synthesis and swelling of agar-based acrylate superabsorbent hydrogel for irrigation water conservation

This study reports the synthesis of novel agar/poly methacrylic acid/poly acrylic acid (AG/PMAc/PAc) superabsorbent hydrogels via gamma radiation and their subsequent urea modification to enhance swelling and water retention for agricultural applications. The superabsorbent hydrogels were prepared by irradiating aqueous mixtures of varying agar concentrations with methacrylic acid/acrylic acid (MAc/Ac) monomers, followed by urea treatment at different cycles and concentrations. The morphological characteristics and chemical structures were confirmed by SEM and FTIR, respectively. The maximum swelling occurred at 6 % agar and 1 % urea modification. Remarkably, the 1 % urea-modified hydrogel displayed a 41.1 % swelling increase and 236.4 % enhancement after the second modification cycle compared to unmodified samples. Water retention studies showed the modified hydrogel retained 53.2 % moisture after 14 days versus the complete drying of unmodified hydrogels. Soil application studies demonstrated the modified hydrogel increased moisture content by 177.3 % after 20 days, promoting better growth with 30 % more leaves and 38.9 % higher stem length in Vicia faba plants versus controls. This novel radiation-synthesized, urea-modified hydrogel with exceptional swelling and moisture retention capabilities shows promising potential for sustainable agricultural irrigation and crop productivity enhancement under water-deficit conditions.

Physical characterization of agar-based biodegradable films derived from nonhazardous laboratory waste

Globally, approximately 2.12 billion tons of waste are annually disposed of, with laboratories significantly contributing across diverse waste streams. Effective waste management strategies are crucial to mitigate environmental impact and promote sustainability within scientific communities. This study addresses the challenges by introducing a novel method that transforms laboratory media waste into a valuable biopolymer named “Agastic.” The process involves repurposing agar extracted from bulk laboratory waste, blending it with bio-based plasticizers to produce Agastic sheets exhibiting mechanical properties comparable to traditional bioplastics. Using response surface methodology (RSM) and central composite design (CCD), optimal concentrations of agar (1.5–2.5% w/v), glycerol (0.25–1% v/v), and ethanolamine (0.5–1.5% v/v) were determined. Predictions from Design Expert software indicated impressive tensile strength up to 14.31 MPa for AGA-1 and elongation at break up to 52% for AGA-2. Fourier Transform Infrared Spectroscopy (FTIR) analysis confirmed agarose structural features in AGA-1 and AGA-2. Thermogravimetric analysis (TGA) showed polysaccharide-related breakdown between 38°C and 280°C in AGA-1, peaking at 299.36°C; AGA-2 exhibited diverse thermal decomposition up to 765°C, suggesting their biodegradable potential in packaging applications. Scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDS) analysis confirmed nontoxic nature of Agastic and preserved morphological integrity in both samples. Soil degradation studies revealed AGA-1 and AGA-2 losing 71.31% and 70.88% of weight, respectively, over 15 days. This innovation provides a sustainable pathway to repurpose laboratory waste into eco-friendly bioplastics, particularly suitable for moisture-sensitive packaging such as nursery applications. These findings underscore Agastic films’ promise as environmentally friendly alternatives to traditional plastics, supporting circular bioeconomy principles and significantly reducing ecological impacts associated with plastic waste.

Triboelectric Nanogenerator Made with Stretchable, Antibacterial Hydrogel Electrodes for Biomechanical Sensing.

Triboelectric nanogenerators (TENGs) have attracted widespread attention as a promising candidate for energy harvesting due to their flexibility and high power density. To meet diverse application scenarios, a highly stretchable (349%), conductive (1.87 S m-1), and antibacterial electrode composed of carbon quantum dots/LiCl/agar-polyacrylamide (CQDs/LiCl/agar-PAAm) dual-network (DN) hydrogel is developed for wearable TENGs. Notably, the concentration of agar alters the pore spacing and pore size of the DN hydrogel, thereby impacting the network cross-linking density and the migration of conductive ions (Li+ and Cl-). This variation further affects the mechanical strength and conductivity of the hydrogel electrode, thus modulating the mechanical stability and electrical output performance of the TENGs. With the optimal agar content, the tensile strength and conductivity of the hydrogel electrode increase by 211 and 719%, respectively. This enhancement ensures the stable output of TENGs during continuous operation (6000 cycles), with open-circuit voltage, short-circuit current, and transferred charge increasing by 200, 530, and 155%, respectively. Additionally, doping with CQDs enables the hydrogel electrode to effectively inhibit the Gram-negative bacterium Escherichia coli. Finally, the TENGs are utilized as a self-power smart ring for efficient and concise information transmission via Morse code. Consequently, this study introduces a creative approach for designing and implementing multifunctional, flexible wearable devices.

Cell wall integrity modulates HOOKLESS1 and PHYTOCHROME INTERACTING FACTOR4 expression controlling apical hook formation.

Formation of the apical hook in etiolated dicot seedlings results from differential growth in the hypocotyl apex and is tightly controlled by environmental cues and hormones, among which auxin and gibberellins (GAs) play an important role. Cell expansion is tightly regulated by the cell wall, but whether and how feedback from this structure contributes to hook development is still unclear. Here, we show that etiolated seedlings of the Arabidopsis (Arabidopsis thaliana) quasimodo2-1 (qua2) mutant, defective in pectin biosynthesis, display severe defects in apical hook formation and maintenance, accompanied by loss of asymmetric auxin maxima and of differential cell expansion. Moreover, qua2 seedlings show reduced expression of HOOKLESS 1 (HLS1) and PHYTOCHROME INTERACTING FACTOR 4 (PIF4), which are positive regulators of hook formation. Treatment of wild-type seedlings with the cellulose inhibitor isoxaben (isx) also prevents hook development and represses HLS1 and PIF4 expression. Exogenous GAs, loss of DELLA proteins or HLS1 overexpression partially restore hook development in qua2 and isx-treated seedlings. Interestingly, increased agar concentration in the medium restores, both in qua2 and isx-treated seedlings, hook formation, asymmetric auxin maxima and PIF4 and HLS1 expression. Analysis of plants expressing a FRET-based GA sensor indicate that isx reduces accumulation of GAs in the apical hook region in a turgor-dependent manner. Lack of the cell wall integrity sensor THESEUS 1, which modulates turgor loss point, restores hook formation in qua2 and isx-treated seedlings. We propose that turgor-dependent signals link changes in cell wall integrity to the PIF4-HLS1 signalling module to control differential cell elongation during hook formation.

Direct shoot regeneration from cotyledonary node of Uraria picta (Jacq.) Desv. ex DC., an important plant of dashmula drugs, and assessment of genetic fidelity, metabolic profiling, and anti-diabetic activity

Uraria picta root is used in the polyherbal product ‘Dashmula’. Its exploitation for formulation preparation has depleted its availability, leading to medicine adulteration. Direct shoot regeneration from the cotyledonary node holds promise as a source of raw material. This study aimed to develop a regeneration protocol for U. picta and validate its genetic and metabolic fidelity. The seeds of U. picta showed low germination rates, prolonged dormancy, and poor viability. Root exploitation in the wild poses a threat to its availability in nature. Seedling’s derived cotyledonary nodes cultured on B5 medium supplemented with BAP (0.5–3 mg L−1), Kinetin (0.5–3 mg L−1), Thidiazuron (0.01–1 mg L−1), and meta-Topolin (0.1–4 mg L1). To address hyperhydricity in regenerated shoots, cotyledonary nodes were cultured on high-agar concentration media. Microshoots were exposed to IBA solution (50–800 mg L−1) pulse treatment for rooting. Tissue-cultured plants genetic fidelity was assessed using ISSR and SCoT markers, while metabolic fidelity was studied with HRMS. The chlorophyll content, antioxidant, and antidiabetic activity of micropropagated plants were evaluated. The highest shoot regeneration frequency, with a maximum of 6.57±0.278 shoots per explant, was achieved using 2 mg L−1meta-Topolin. The shoots were elongated, had expanded leaves, and were hyperhydrated. BAP (2 mg L−1) induced a maximum of 9.83±0.333 shoot buds per explant. BAP caused explant browning, profuse callus formation, dwarfing, and hyperhydric shoots. Hyperhydricity was alleviated with a higher agar concentration (1 %). IBA (400 mg L−1) induced a maximum of 2.18±0.090 roots per shoot and a root length of 9.23±0.033 cm. Tissue-cultured and mother plants exhibited clonal fidelity, similar metabolite and chlorophyll content, strong antioxidant activity, and equal efficacy for inhibiting α-amylase and α-glucosidase. This method can propagate elite clones of U. picta and offer its improvement via genetic transformation.

Optical-resolution photoacoustic microelastography system for elasticity mapping: Phantom study and practical application.

Elastography is a noninvasive technique for characterizing the mechanical properties of biological tissues. Conventional methods have limitations in resolution and sensitivity, hindering disease detection in clinical diagnostics. To address these issues, this study developed an optical-resolution photoacoustic microelastography (OR-PAME) system. Using an agar tissue phantom with varying agar concentrations and contrast agents, PAME evaluated elasticity distribution under compression in both lateral and axial dimensions. It indirectly measured elastic properties by correlating photoacoustic responses, temporal lags, and induced displacement. We also applied the system to the study of the distribution of elastic characteristics of the liver tissue after ablation, which confirmed the potential of OR-PAME in the study of elastic characteristics. Quantitative analysis showed greater lateral displacement in regions with reduced agar concentrations, indicating decreased stiffness. PAME also detected vertical displacement along the axial plane, validating its efficacy in elastographic imaging. By improving resolution and penetration, PAME provides superior visualization of elasticity distribution. Its methodology correlates microstructural alterations with tissue biomechanics, holding potential implications in medical diagnostics.

Diffusion coefficients in scaffolds made with temperature controlled cryoprinting and an ink made of sodium alginate and agar

Temperature Controlled Cryoprinting (TCC), is a tissue engineering technique wherein each deposited voxel is frozen with precise control over cooling rates and the direction of freezing. This control allows for the generation of ice crystals with controlled shape and orientation. Recently we found that the macroscale fidelity of the TCC print is substantially improved by using a 3D printing ink composed of a mixture of two compounds: one that solidifies through chemical crosslinking (sodium alginate) and another that solidifies through physical (thermal) effects (agar). In this study we examine the hypothesis that the combination of sodium alginate and agar, affects also the fidelity of the microstructure and thereby the diffusivity of the scaffold. The ability of this technology to generate controlled diffusivity within the tissue scaffold was examined with a directional solidified TCC sample using fluorescence recovery after photobleaching (FRAP) and scanning electron microscope (SEM). We find that the diffusion coefficient in m2/s × 10−10 is: 1.62 ± 1.27 for the unfrozen sample, 2.40 ±1.54 for the rapidly frozen sample and 9.72± 4.50 for the slow frozen sample. This points to two conclusions. One is that the diffusivity is slow frozen samples is higher than that in unfrozen samples and in rapidly frozen sample. A second observation is that a relatively narrow range of diffusivity variance was obtained when using 2%w/v sodium alginate and 2%w/v of agar. However, when the concentration of agar was reduced to 0.5w/v a much wider spread of diffusivities was measure, 4.07±1.65. This suggests that the addition of agar has also an effect on the microscale fidelity, and consequently the diffusivity. The anisotropic diffusion properties of TCC-printed directional solidification samples were also validated through both FRAP and SEM.

MORPHOLOGY AND HYDROPHOBICITY OF AGAR, BEESWAX, AND AGAR-BEESWAX EMULSION COATED ON POROUS ALUMINA SUPPORT

Membrane degassing technology is based on the principle of hydrophobicity. Up-to-date, the membrane degasifier is industrially produced by extrusion and then stretched to form a hollow fiber shape with long narrow pores along membrane length. Typical degasifiers are engineered with polypropylene (PP) due to its high toughness and flexibility. However, finding environmentally safe materials at a low cost for replacement for PP would be worth investigating. In this work, agar, beeswax, and their emulsion were coated on a tubular alumina membrane for use as a selective layer of the membrane degasifier. The agar solution with different concentrations between 1 and 4 wt% was coated on the alumina membrane support to create a pore network. Beeswax was coated on agar film to enhance the hydrophobicity. SEM images showed that the increase in the concentrations of agar led to a decreased pore size of the selective layer. Moreover, the contact angle increased up to 100° when the concentration of agar solution increased to 4 wt%. The increase in contact angle to 120° was obtained when the beeswax was coated, appropriate for hydrophobic applications.

A straightforward procedure to build a non-toxic relaxometry phantom with desired T1 and T2 times at 3T

ObjectiveTo prepare and analyze soy-lecithin-agar gels for non-toxic relaxometry phantoms with tissue-like relaxation times at 3T.MethodsPhantoms mimicking the relaxation times of various tissues (gray and white matter, kidney cortex and medulla, spleen, muscle, liver) were built and tested with a clinical 3T whole-body MR scanner. Simple equations were derived to calculate the appropriate concentrations of soy lecithin and agar in aqueous solutions to achieve the desired relaxation times. Phantoms were tested for correspondence between measurements and calculated T1 and T2 values, reproducibility, spatial homogeneity, and temporal stability. T1 and T2 mapping techniques and a 3D T1-weighted sequence with high spatial resolution were applied.ResultsExcept for the liver relaxation phantom, all phantoms were successfully and reproducibly produced. Good agreement was found between the targeted and measured relaxation times. The percentage deviations from the targeted relaxation times were less than 3% for T1 and less than 6.5% for T2. In addition, the phantoms were homogeneous and had little to no air bubbles. However, the phantoms were unstable over time: after a storage period of 4 weeks, mold growth and also changes in relaxation times were detected in almost all phantoms.ConclusionSoy-lecithin-agar gels are a non-toxic material for the construction of relaxometry phantoms with tissue-like relaxation times. They are easy to prepare, inexpensive and allow independent adjustment of T1 and T2. However, there is still work to be done to improve the long-term stability of the phantoms.

Dual-channel air-pulse optical coherence elastography for frequency-response analysis

Microliter air-pulse optical coherence elastography (OCE) has recently been proposed for the characterization of soft-tissue biomechanics using transient, sub-nanometer to micrometer-scale natural frequency oscillations. However, previous studies have not been able to provide real-time air-pulse monitoring during OCE natural frequency measurement, which could lead to inaccurate measurement results due to the unknown excitation spectrum. To address this issue, we introduce a dual-channel air-pulse OCE method, with one channel stimulating the sample and the other being simultaneously measured with a pressure sensor. This allows for more accurate natural frequency characterization using the frequency response function, as proven by a comprehensive comparison under different conditions with a diverse range of excitation spectra (from broad to narrow, clean to noisy) as well as a diverse set of sample response spectra. We also demonstrate the capability of the frequency-response analysis in distinguishing samples with different stiffness levels: the dominant natural frequencies increased with agar concentrations (181–359 Hz, concentrations: 1–2%, and maximum displacements: 0.12–0.47 µm) and intraocular pressures (IOPs) for the silicone cornea (333–412 Hz, IOP: 5–40 mmHg, and maximum displacements: 0.41–0.52 µm) under a 200 Pa stimulation pressure. These frequencies remained consistent across different air-pulse durations (3 ms to 35 ms). The dual-channel OCE approach that uses transient, low-pressure stimulation and high-resolution imaging holds the potential to advance our understanding of sample frequency responses, especially when investigating delicate tissues such as the human cornea in vivo.

Establishment of Effective Callus Induction in the Economically Important Brown Seaweed Ecklonia cava

The edible brown seaweed, Ecklonia cava, is highly valued for its bioactive compounds, and is widely used in food supplements and functional foods. The increasing demand for this seaweed in the food industry emphasizes the necessity for sustainable cultivation practices. This study focused on inducing callus in the meristem and stipe of E. cava using different culture media: Provasoli’s enriched seawater medium (PESI), enriched artificial seawater medium (ESAW), artificial enriched seawater medium (ASP2), or Von Stosch’s enriched seawater medium (VS). Various abiotic stress factors (photoperiod, agar concentration, and temperature), growth regulators, carbon sources, polyamines, and plasma treatments were explored for their impact on callus induction. Both stipe and meristem explants developed callus within three to six weeks across all media except ASP2. Callus development was favored at temperatures between 8 to 13 °C and in the absence of light. Stipe explants showed a higher callus induction rate (up to 65.59 ± 6.24%) compared to meristem (up to 57.53 ± 8.32%). Meristem explants showed optimal callus induction in PESI medium with a low concentration of indole-3-acetic acid (IAA; 40.93 ± 8.65%). However, higher concentrations of IAA and 1-naphthaleneacetic acid (NAA) reduced meristem callus induction. Stipe showed high induced-callus (up to 50.37 ± 5.17%) in PESI medium with low concentrations of IAA, NAA, and 6-benzylaminopurine (BAP). Both stipe and meristem explants induced largest callus at 2% sucrose, but higher carbon source concentrations reduced callus induction. Spermine (Spm) at 1 µM resulted in high induced calluses; however, increasing Spm concentrations decreased callus induction. This tissue culture technique not only supports mass cultivation of E. cava, but also holds potential for extending to other seaweed species, contributing to the sustainability of seaweed stocks for the food industry.

Utilization Of Coconut Dregs As An Alternative Medium For The Growth Of Bacillus Subtilis And Escherchia Coli

Coconut dregs are waste produced after processing coconuts into coconut oil. Coconut pulp has a high nutritional content which can be used for bacterial growth. The nutritional content of coconut dregs is 38.1% carbohydrates, 5.6% crude protein, 16.3% crude fat, 31.6% crude fiber, 2.6% ash content and 5.5% water content. The research used coconut dregs as an alternative medium for the growth of gram-negative and gram-positive bacteria. In the trials, B. subtilis and E. coli bacteria were used. The type of research used was a true experiment with a completely randomized design. The results of the research showed that the highest average number of colonies on the coconut dregs alternative media was in treatment A1, namely the average of B.subtilis colonies was 50.6 x 10² CFU/mL and E.coli 36 .6 x 10² CFU/mL while the control media averaged B.subtilis colonies 75 x 10² CFU/mL and E.coli 86.3 x 10² CFU/mL. The results of statistical tests using anova p<0.05 with a sig value of 0.001 show that there is an influence of differences in the concentration of coconut dregs and agar as an alternative medium for bacterial growth. The post hoc test compares the concentration between treatment A1 and control with a sig p value of >0.05 (0.250), namely There is no significant difference, while the concentration between treatments A2, A3 and A4 with control has a sig p value <0.05, namely 0.000, meaning there is a significant difference. So treatment A1 is the best treatment for the growth of B.subtilis and E.coli bacteria.

Modification of Media Formulation and Agar Concentration to Improve Pitcher Plant (Nepenthes mirabilis (Lour.) Druce) Micropropagation for Conservation and Microfloriculture Development

Modification of Media Formulation and Agar Concentration to Improve Pitcher Plant (Nepenthes mirabilis (Lour.) Druce) Micropropagation for Conservation and Microfloriculture Development

Estimation of the Proton Resonance Frequency Coefficient in Agar-based Phantoms.

Agar-based phantoms are popular in high intensity focused ultrasound (HIFU) studies, with magnetic resonance imaging (MRI) preferred for guidance since it provides temperature monitoring by proton resonance frequency (PRF) shift magnetic resonance (MR) thermometry. MR thermometry monitoring depends on several factors, thus, herein, the PRF coefficient of agar phantoms was estimated. Seven phantoms were developed with varied agar (2, 4, or 6% w/v) or constant agar (6% w/v) and varied silica concentrations (2, 4, 6, or 8% w/v) to assess the effect of the concentration on the PRF coefficient. Each phantom was sonicated using varied acoustical power for a 30 s duration in both a laboratory setting and inside a 3T MRI scanner. PRF coefficients were estimated through linear trends between phase shift acquired using gradient sequences and thermocouple-based temperatures changes. Linear regression (R 2 = 0.9707-0.9991) demonstrated a proportional dependency of phase shift with temperature change, resulting in PRF coefficients between -0.00336 ± 0.00029 and -0.00934 ± 0.00050 ppm/°C for the various phantom recipes. Weak negative linear correlations of the PRF coefficient were observed with increased agar. With silica concentrations, the negative linear correlation was strong. For all phantoms, calibrated PRF coefficients resulted in 1.01-3.01-fold higher temperature changes compared to the values calculated using a literature PRF coefficient. Phantoms developed with a 6% w/v agar concentration and doped with 0%-8% w/v silica best resemble tissue PRF coefficients and should be preferred in HIFU studies. The estimated PRF coefficients can result in enhanced MR thermometry monitoring and evaluation of HIFU protocols.

<i>In Vitro</i> Study of Fitness Parameters in Fungicide-Resistant and -Sensitive <i>Venturia inaequalis</i> Isolates

The developing resistance of Venturia inaequalis to toxicants commonly used in systemic fungicides against apple scab has reduced their effectiveness, causing substantial fruit loss in orchards. To improve the situation and manage the resistance, a thorough analysis of the fitness potential among different pathogen biotypes, particularly those resistant to fungicides, is needed. In this study, the mycelial growth of V. inaequalis isolates with baseline sensitivity and resistance to one or more fungicides was assessed in vitro at four temperatures (6, 18, 27, and 30°C) and three agar concentrations in the nutrient medium (2, 4, and 6% m/V). Except for the mycelial growth at 27°C, the indicators of fitness predicted in vitro did not differ significantly between the V. inaequalis isolates with multiple resistance to fungicides and the biotypes with baseline sensitivity.

Effect of various concentrations of agar and sucrose on growth and tuberization of four Potato (Solanum tuberosum L.) varieties under in vitro, invivo conditions

The study tends to evaluate the effect of different concentrations of agar treatment (5, 7, and 9 g.l-1) with sucrose (20, 30, and 40 g.l-1) on in vitro shoot regeneration and rooting in one step using tuber-eyes and node explants of four potatoes (Solanum tuberosum L) varieties “Sagitta, Challenger, SM 13–132– 05 and Taurus”, and minitubers production under greenhouses conditions which are going to be grown in Kurdistan -Iraq. The results showed that SM 13–132– 05 cultivar was superior upon the other cultivars under in vitro conditions through multiplication tests (Agar concentration 7 g.l-1 and sucrose concentration 30 g.l-1) and greenhouse conditions by producing the highest shoot multiplication (3.17 shoots/ explant, 12.84 leaves/ explant and 14.51cm mean length of roots) and the best number of minitubers (5.72 minitubers/ plantlet) in greenhouse. Whereas, Challenger had the lowest number of minitubers (3.75/ plantlet). On the other hand, there was no significant differences in the effect of the different concentrations of Agar and sucrose on the four cultivars in terms of the rooting percentage.

Optimized swarming motility assay to identify anti-virulence products against Vibrio parahaemolyticus, a pathogen of farmed shrimp

Swarming motility is a type of movement used by pathogenic flagellated bacteria as virulence factor to colonize surfaces and cause damage to the host. Vibrio parahaemolyticus is a pathogenic flagellated bacterium that increases its virulence by switching from swimmer to swarming cells. The hosts of pathogenic V. parahaemolyticus include farmed shrimp. Therefore, methods to detect and quantify this movement are important to control shrimp diseases caused by pathogenic V. parahaemolyticus strains. We developed an optimized swarming motility assay by identifying the most optimal type of agar, and drying time of the culture medium, agar concentration and volume of the bacterial culture to achieve the fastest swarming motility during the migration of V. parahaemolyticus on Petri dishes during a 24-hour incubation period. The method includes data analysis that could be used as a tool to identify potential anti-virulence products by comparing the slopes of the linearized diameters of the swarming halos of bacteria treated with the products, as they migrate on Petri dishes over a 24-hour incubation period.Here we report:•A simple method for detection and quantification of swarming motility halos of V. parahaemolyticus bacteria.•A method that could be used as a tool to identify potential anti-virulence products.

Characterization of the concentration of agar-based soft tissue mimicking phantoms by impact analysis

In various medical fields, a change of soft tissue stiffness is associated with its physio-pathological evolution. While elastography is extensively employed to assess soft tissue stiffness in vivo, its application requires a complex and expensive technology. The aim of this study is to determine whether an easy-to-use method based on impact analysis can be employed to determine the concentration of agar-based soft tissue mimicking phantoms. Impact analysis was performed on soft tissue mimicking phantoms made of agar gel with a mass concentration ranging from 1% to 5%. An indicator Δt is derived from the temporal variation of the impact force signal between the hammer and a small beam in contact with the sample. The results show a non-linear decrease of Δt as a function of the agar concentration (and thus of the sample stiffness). The value of Δt provides an estimation of the agar concentration with an error of 0.11%. This sensitivity of the impact analysis based method to the agar concentration is of the same order of magnitude than results obtained with elastography techniques. This study opens new paths towards the development of impact analysis for a fast, easy and relatively inexpensive clinical evaluation of soft tissue elastic properties.

Environmental physical factors produce mitotic aberration and multicellularity in the ovarian cancer cell line SKOV3

The spread of ovarian cancer (OC) to the coelomic cavity triggers the secretion and accumulation of ascitic fluid (AF). Although its biochemical composition has been well studied, less is known about the implications of physical factors such as the pH and the mechanical properties of the AF for the malignancy of tumor cells. In this work, we investigated the effect of pH and the mechanical properties of AF on cell proliferation and mitotic morphology. We employed biopsies from patients with OC and the SKOV3 cell line as an in vitro model of OC with HeLa cells as controls. Sections of each tumor were stained with HE, analyzed, and related to clinical data. AF from patients with OC exhibited an alkaline pH (ranging from 7.3 to 7.8). Compared to control conditions, the 3 AFs significantly enhanced the proliferation of SKOV3 and HeLa cells. These effects were more pronounced at a more alkaline pH. In addition, we found that AFs have different densities that correlated with a significant increase in multinucleated tumor cells and severe morphological defects in cells undergoing mitosis. In agreement with these data, we found that higher concentrations of soft agar provoked significantly higher numbers of multinucleated and morphologically abnormal SKOV3 cells with no effect on HeLa cells.We conclude that an alkaline pH and greater rigidity could enhance the metastatic potential of OC cells. We propose that these two physical factors could be parameters of clinical importance as predictors of malignancy.

Mechanism of interaction between agar and corn starch: Towards improved properties of starch-based cryogel

In this study, agar/corn starch cryogels with different morphologies and characteristics were synthesized using sol, gel, and freeze-drying techniques. The addition of agar increased the gelatinization temperature of starch and decreased the gelatinization enthalpy, thereby inhibited the gelatinization process of starch. The rheological data revealed that the addition of agar accelerated the gelatinization process of the agar/starch binary system and significantly increased the storage modulus of the hydrogel. Fourier transform infrared spectroscopy, X-ray diffraction analysis, and scanning electron microscopy demonstrated that agar disrupted the retrogradation and crystal structure of starch. A lower concentration of agar destroyed the network structure formed by starch and increased the pore size of cryogel. However, the fiber-bundle structure formed in the large pores after increasing the agar content made the cryogel network more compact. However, this led to marginal increase in cryogel density which endowed the cryogel with significantly improved compressive strength (5.01 MPa) and toughness. Therefore, the incorporation of agar into starch to prepare a composite cryogel is an effective approach for improving the properties of starch-based cryogels.