Rotenone encapsulated in pH-responsive alginate-based microspheres reduces toxicity to zebrafish.

Rotenone is a botanical pesticide and has long been used for control of insect pests and also as a natural piscicide for management of fish populations in many countries. Field application for pest control, however, often encounters the movement of rotenone into surface water due to spray drift or surface runoff after rainfall, which could potentially result in water pollution and unexpected death of fishes. To minimize its effect on freshwater and the problem of fish dying, one solution was to encapsulate rotenone in specific microspheres, limiting its release and reducing its toxicity since rotenone can be quickly degraded under sunlight. In this study, pH-responsive alginate-based microspheres were synthesized to encapsulating rotenone, which were designated as rotenone beads. The rotenone beads, along with alginate beads (devoid of rotenone) were characterized and evaluated for their responses to pH and effects on zebrafish. Results showed that the microspheres had high loading efficiency (4.41%, w/w) for rotenone, and rotenone beads well responded to solution pH levels. The cumulative release rates of rotenone from the beads were 27.91%, 42.72%, and 90.24% at pH 5.5, 7.0, and 9.0, respectively. Under acidic conditions, the rotenone release rate was lower due to hydrogen bonding. On the contrary, rotenone became more quickly released at the high pH due to intermolecular repulsion. The toxicity of rotenone beads to zebrafish and fish embryos at a pH of 5.5 was reduced by 2- and 4-fold than chemical rotenone. Since pH levels in most freshwater lakes, ponds, and streams vary from 6 to 8, rotenone release from the beads in such freshwater could be limited. Thus, the synthesized rotenone beads could be relatively safely used for pest control with limited effects on freshwater fishers.

Surface functionalized magnetic nanoparticles shift cell behavior with on/off magnetic fields.

Magnetic nanoparticles (MNPs) are used as contrast agents and targeted drug delivery systems (TDDS) due to their favorable size, surface charge, and magnetic properties. Unfortunately, the toxicity associated with MNPs limits their biological applications. Surface functionalization of MNPs with selective polymers alters the surface chemistry to impart better biocompatibility. We report the preparation of surface functionalized MNPs using iron oxide NPs (MNPs), poly (lactic-co-glycolic acid) (PLGA), and sodium alginate via co-precipitation, emulsification, and electro-spraying, respectively. The NPs are in the nanosize range and negatively charged. Morphological and structural analyses affirm the surface functionalized nanostructure of the NPs. The surface functionalized MNPs are biocompatible, and demonstrate enhanced intracellular delivery under an applied magnetic field (H), which evinces the targeting ability of MNPs. After NP treatment, the physico-mechanical properties of fibroblasts are decided by the selective MNP uptake under "on" or "off" magnetic field conditions. We envision potential use of biocompatible surface functionalized MNP for intracellular-, targeted-DDS, imaging, and for investigating cellular mechanics.

Preparation and biocompatibility of demineralized bone matrix/sodium alginate putty.

Demineralized bone matrix (DBM) powder is widely used for bone regeneration due to its osteoinductivity and osteoconductivity. However, difficulties with handling, tendency to migrate from graft sites and lack of stability after surgery sometimes limit the clinical utility of this material. In this work, the possibility of using sodium alginate (ALG) carrier to deliver DBM powder was assessed. DBM-ALG putty with the DBM:ALG weight ratio of 5:5, 6:4, 7:3, 8:2 were prepared, respectively. The properties of the formed composite, including discrete degree, washout property, pH, equilibrium swelling as well as cytotoxicity in vivo, were adopted to ascertain the optimal ratio of DBM and ALG. The discrete diameter increased from 1.25 cm (5:5) to 2.08 cm (8:2) with the increase of DBM content. There was significant difference between the 8:2 group and the other groups in discrete diameter. The ratio of DBM had a significant effect on the swelling value. The pH of composites showed an increase trend with the DBM ratio's increase, when the ratio reached 7:3, the pH (7.22) was approximately equal to the body fluid. The proliferation of MC3T3-E1 cells was inhibited in the 5:5, 6:4 and 7:3 groups, while a slightly increased in the 8:2 group. The DBM-ALG with the optimal ratio of 7:3 was confirmed based on the results of the above mentioned. The histocompatibility of DBM-ALG (7:3) was examined using a rat model in which the materials were implanted subcutaneously, compared with the polyethylene, ALG and DBM. The study in vivo showed DBM-ALG (7:3) had a lower inflammatory response than DBM, a higher vascularization than ALG. The osteoinduction of DBM-ALG (7:3) was evaluated by co-culturing with MC3T3-E1 in vitro, compared with the DMEM, ALG and DBM. The results indicated calcification area in the DBM-ALG group was similar to that in the DBM group, larger than ALG group and DMEM group. The DBM-ALG (7:3) putty is promising as a directly injectable graft for repair of bone defect.

Effects of alginate on stability and ecotoxicity of nano-TiO2 in artificial seawater.

The large-scale use of titanium dioxide nanoparticles (nano-TiO2) in consumer and industrial applications raised environmental health and safety concerns. Potentially impacted ecosystems include estuarine and coastal organisms. Results from ecotoxicological studies with nano-TiO2 dispersed in salt exposure media are difficult to interpret due to fast flocculation and sedimentation phenomena affecting the dispersion stability. The goal of this study was to investigate the stabilisation effect of alginate on uncoated nano-Ti22 in artificial seawater dispersions used in ecotoxicity bioassays. The most effective stabilisation was obtained at alginate concentration of 0.45 g/L after sonicating dispersions for 20 min (100 W). The size distribution remained constant after re-suspension, indicating that no agglomeration occurred after deposition. Ecotoxicity tests on Artemia franciscana and Phaeodactylum tricornutum did not show any adverse effects related to the presence of alginate in the exposure media, and provided evidence on possible reduced bioavailability of nano-TiO2. The suitable concentration of alginate is recommended to occur on a case-by-case basis.

Preclinical assessment of ß-d-mannuronic acid (M2000) as a non-steroidal anti-inflammatory drug.

CONTEXT: ß-d-Mannuronic acid (M2000) has shown its therapeutic effects with the greatest tolerability and efficacy in various experimental models such as experimental autoimmune encephalomyelitis (EAE), adjuvant induced arthritis (AIA), nephrotic syndrome, and acute glomerulonephritis. Despite pharmacological effects of ß-D-mannuronic acid, there have been no systematic toxicological studies on its safety so far. OBJECTIVE: The study was designed to determine the acute and subchronic toxicity of ß-D-mannuronic acid, an anti-inflammatory agent, in healthy male NMRI mice and Wistar rats, respectively. MATERIALS AND METHODS: For the acute toxicity study, the animals received orally five different single doses of ß-D-mannuronic acid and were kept under observation for 14 d. In the subchronic study, 24 Wistar male rats were divided into four groups and were treated orally (gavage) once daily with test substance preparation at dose levels of 0, 50, 250, and 1250 mg/kg body weight for at least 63 consecutive days (9 weeks). Mortality, clinical signs, body weight changes, hematological and biochemical parameters, gross findings, organ weights, and histopathological determinations were monitored during the study. RESULTS: The results of acute toxicity indicated that the LD50 of ß-D-mannuronic acid is 4.6 g/kg. We found no mortality and no abnormality in clinical signs, body weight, relative organ weights, or necropsy in any of the animals in the subchronic study. Additionally, the results showed no significant difference in hematological, biochemical, and histopathological parameters in rats. CONCLUSIONS: Our results suggest that ß-D-mannuronic acid is relatively safe when administered orally in animals.

Comparison of the cytotoxicities and wound healing effects of hyaluronan, carbomer, and alginate on skin cells in vitro.

OBJECTIVE: To compare the cytotoxicities and efficacy of hyaluronan (HA), carbomer, and sodium alginate on repairing thermal-injured cells and promoting cell migration. DESIGN: The 3-(4,5)-dimethylthiahiazo(-z-y1)-3,5-di-phenytetra-zoliumromide method was used to evaluate the cytotoxicities of HA, carbomer, and sodium alginate on L929 mouse fibroblasts and their repairing ability to thermal-injured HaCaT keratinocytes. A scratch test was used to observe the effects of the 3 materials on cell migration. RESULTS: Hyaluronan with different molecular weights were nontoxic, even at the concentration of 0.5%, whereas carbomer and sodium alginate showed mild or moderate cytotoxicities when their concentrations were higher than 0.1%. Cell viability and cell density of the thermal-injured keratinocytes treated with HA (600, 1070, and 1500 kDa) were increased significantly compared with that of model control (P < .05), whereas carbomer aggravated cell injury, and sodium alginate had no obvious repairing ability. Hyaluronan promoted cell migration significantly with higher cell density in the scratch area, compared with the control after culture for 48 hours; both carbomer and sodium alginate inhibited the cell migration, and carbomer altered the cell morphology completely. CONCLUSIONS: Hyaluronan can repair cell injury and promote cell migration and proliferation. It also has good biocompatibility. As a new type of hydrogel matrix, HA is superior to carbomer and sodium alginate if it is used in wound caring preparations.

Cytotoxic effects of denture adhesives on primary human oral keratinocytes, fibroblasts and permanent L929 cell lines.

BACKGROUND: To date, there have been very little data on the cytotoxic responses of different cell lines to denture adhesives. OBJECTIVE: To determine the cytotoxicity of three denture adhesives on primary human oral keratinocytes (HOKs), fibroblasts (HOFs) and permanent mouse fibroblasts cell lines (L929). METHODS: Three commercial denture adhesives (two creams and one powder) were prepared for indirect contact using the agar diffusion test, as well as extracts in MTT assay. The results of the MTT assay were statistically analysed by one-way anova and Tukey's test (p < 0.05). RESULTS: All of the tested denture adhesives showed mild to moderate cytotoxicity to primary HOKs (p < 0.001), whereas none of three was toxic to L929 cells (p > 0.05) in both assays. For primary HOFs cultures, slight cytotoxicity was observed for one of the products from the agar diffusion test and undiluted eluates of all tested adhesives with MTT assay (p < 0.01). CONCLUSION: Denture adhesives are toxic to the primary HOKs and HOFs cultures, whereas non-toxic to L929 cells. The results suggest that primary human oral mucosal cells may provide more valuable information in toxicity screening of denture adhesives.

Cell(MC3T3-E1)-printed poly(ϵ-caprolactone)/alginate hybrid scaffolds for tissue regeneration.

A new cell-printed scaffold consisting of poly(ϵ-caprolactone) (PCL) and cell-embedded alginate struts is designed. The PCL and alginate struts are stacked in an interdigitated pattern in successive layers to acquire a three-dimensional (3D) shape. The hybrid scaffold exhibits a two-phase structure consisting of cell (MC3T3-E1)-laden alginate struts able to support biological activity and PCL struts able to provide controllable mechanical support of the cell-laden alginate struts. The hybrid scaffolds exhibit an impressive increase in tensile modulus and maximum strength compared to pure alginate scaffolds. Laden cells are homogeneously distributed throughout the alginate struts and the entire scaffold, resulting in cell viability of approximately 84%.

Alginate enhances excretion and reduces absorption of strontium and cesium in rats.

Alginate (ALA), which is an intercellular polysaccharide associated with brown algae, is used as a food additive, a health food and a medicine. Here, we first examined the adsorption of strontium (Sr) and cesium (Cs) by ALA in vitro, and then evaluated the effects of ALA on absorption and excretion of Sr and Cs in rats, in order to evaluate its potential usefulness for minimizing radiation damage from materials released after a nuclear accident. Both Sr and Cs were concentration-dependently adsorbed by sodium alginate (ALA-Na) in vitro. In rats given diet containing either ALA-Na or calcium alginate (ALA-Ca) for two weeks, the plasma concentration of Sr gradually decreased compared with the controls (normal diet); however, in the case of Cs, the plasma concentration was decreased only in the ALA-Ca group, but not the ALA-Na group. Moreover, we examined the effect of preadministration of diet containing either ALA-Na or ALA-Ca on absorption of Sr and Cs administered orally as the chloride salts to rats. Absorption of both Sr and Cs was reduced in the ALA-Ca group, while absorption of only Sr was reduced in the ALA-Na group. Safety assessments indicated that ALA-Ca is safer than ALA-Na. These results indicate that ALA-Ca reduces absorption and promotes excretion of both Sr and Cs, while ALA-Na does so only for Sr.

Effect of chitosan-alginate nanoparticles and ultrasound on the efficiency of gene transfection of human cancer cells.

BACKGROUND: Gene therapy has been used to treat a variety of health problems, but transfection inefficiency and the lack of safe vectors have limited clinical progress. Fabrication of a vector that is safe and has high transfection efficiency is crucial for the development of successful gene therapy. The present study aimed to synthesize chitosan-alginate nanoparticles that can be used as carriers of the pAcGFP1-C1 plasmid and to use these nanoparticles with an ultrasound protocol to achieve high efficiency gene transfection. METHODS: Chitosan was complexed with alginate and the pAcGFP1-C1 plasmid at different charge ratios to create chitosan-alginate-DNA nanoparticles (CADNs). The average particle size and loading efficiency were measured. Plasmid DNA retardation and integrity were analysed on 1% agarose gels. The effect of CADNs and ultrasound on the efficiency of transfection of cells and subcutaneous tumors was evaluated. RESULTS: In the CADNs, the average size of incorporated plasmid DNA was 600-650 nm and the loading efficiency was greater than 90%. On the basis of the results of the plasmid DNA protection test, CADNs could protect the transgene from DNase I degradation. The transgene product expression could be enhanced efficiently if cells or tumor tissues were first given CADNs and then treated with ultrasound. CONCLUSIONS: The use of CADNs combined with an ultrasound regimen is a promising method for safe and effective gene therapy.

Glucose response of dissolved-core alginate microspheres: towards a continuous glucose biosensor.

Microparticle optical sensors hold potential as implantable smart materials for in vivo analysis. In this work, the reversible response of dissolved-core alginate microspheres containing a homogeneous fluorescence resonance energy transfer (FRET)-based competitive binding assay for glucose was evaluated. The layer-by-layer self assembly technique was used to deposit multilayered nanofilm coatings on the alginate microspheres containing the assay, thereby stabilizing the sensor system when the alginate was de-crosslinked. The response to glucose was then determined in DI water and simulated interstitial fluid (SIF) using a flow cell to establish controlled, dynamic flow conditions for demonstrating reversibility. The glucose sensitivity under dynamic conditions was estimated to be 0.52%/mM glucose in DI water and 0.6%/mM glucose in simulated interstitial fluid; in both cases, the analytical response range was 0-30 mM glucose, covering both physiological (normoglycemia) and pathophysiological range (hyperglycemia and hypoglycemia). The sensor demonstrated a repeatable and reproducible response when tested over a period of one month, under dynamic flow conditions. Finally, in vitro cytotoxicity assays performed with L929 mouse fibroblast cell lines suggested that the dissolved-core alginate microsphere sensor system with nanofilm coating has sufficient biocompatibility for use as implantable glucose biosensors.

Comparative in vitro study on cytotoxicity, antimicrobial activity, and binding capacity for pathophysiological factors in chronic wounds of alginate and silver-containing alginate.

Chronic wounds contain elevated levels of proteases, proinflammatory cytokines, and free radicals. The presence of bacteria further exaggerates the tissue-damaging processes. For successful treatment, the wound dressing needs to manage wound exudates, create a moist environment, inhibit infection, bind pathophysiological factors that are detrimental to wound healing, and provide thermal isolation. Furthermore, it has to relieve pain, be easy to use, show no allergic potency, and not release toxic residues. The present study suggests a comprehensive in vitro approach to enable the assessment of wound dressings to support optimal conditions for wound healing. Three alginate-based wound dressings: alginate alone, alginate containing ionic silver, and alginate with nanocrystalline silver, were tested for biocompatibility, antimicrobial activity, and influence on chronic wound parameters such as elastase, matrix metalloproteases-2, tumor necrosis factor-alpha, interleukin-8, and free radical formation. Alginate was found to bind considerable amounts of elastase, reduce the concentration of proinflammatory cytokines and inhibit the formation of free radicals. Furthermore, alginate showed antibacterial activity and high biocompatibility. Incorporation of silver into alginate fibers increased antimicrobial activity and improved the binding affinity for elastase, matrix metalloproteases-2, and the proinflammatory cytokines tested. Addition of silver also enhanced the antioxidant capacity. However, a distinct negative effect of silver-containing alginates on human HaCaT keratinocytes was noted in vitro.

Synthesis and evaluation of anti-fungal activities of sodium alginate-amphotericin B conjugates.

Sodium alginate (SA) was oxidized using periodate and amphotericin B (AmB) was conjugated via imine and amine linkages to the oxidized alginate. Oxidization drastically reduced the molecular weight (MW) of the alginate. The conjugates were highly water-soluble to the extent of 1000mg/mL making them useful for therapeutic applications. SA-AmB conjugates derived from 20 and 50% oxidized alginate were non-toxic to HEK 293T and RAW 264.7 cell line at 100µg/mL and was also non-hemolytic to human blood at 100µg/mL. In vitro release of AmB into phosphate buffer from the imine conjugates was negligible with less than 0.2% of the drug released in 48h. Capping of residual aldehyde handles using 2-ethanolamine or glycine resulted in increased release of the drug in vitro. Injectable gels of gelatin crosslinked with oxidized alginate incorporating the SA-AmB conjugates as well as AmB were also fabricated and drug release was examined. In vitro release from the gel discs showed that AmB was released to the extent of 15-20% in 2days. The SA-AmB conjugates showed potent anti-fungal activity against C. albicans, C. neoformans and C. parapsilosis. The injectable gels seem to have potential for prolonged release of AmB when implanted.

In vitro and in vivo toxicity assessment of alginate/eudragit S 100-enclosed chitosan-calcium phosphate-loaded iron saturated bovine lactoferrin nanocapsules (Fe-bLf NCs).

Lactoferrin has been known to have antimicrobial properties. This research was conducted to investigate the toxicity of Alginate/EUDRAGIT® S 100-enclosed chitosan-calcium phosphate-loaded Fe-bLf nanocapsules (NCs) by in vitro and in vivo assays. Brine shrimp lethality assay showed that the LC50 value of NCs was more than 1mg/mL which indicated that NCs was not toxic to Brine shrimp. However, the LC50 values for the positive control potassium dichromate at 24h is 64.15µg/mL, which was demostrated the toxic effect against the brine shrimp. MTT cytotoxicity assay also revealed that NCs was not toxic against non-cancerous Vero cell line with IC50 values of 536µg/mL. Genotoxicity studies by comet assay on Vero cells revealed that NCs exerted no significant genotoxic at 100µg/mL without tail or shorter comet tail. Allium cepa root assay carried out at 125, 250, 500 and 1000µg/mL for 24h revealed that the NCs was destitute of significant genotoxic effect under experimental conditions. The results show that there is no significant difference (p>0.05) in mitotic index between the deionized water and NCs treated Allium cepa root tip cells. In conclusion, no toxicity was observed in NCs in this study. Therefore, nontoxic NCs has the good potential to develop as a therapeutic agent.

Novel oleyl amine-modified polymannuronic acid micelle loading tacrolimus for therapy of allergic conjunctivitis.

Marine polysaccharide-based nanomaterial attracted considerable attention due to its biocompatibility and biodegradability. Here, a novel polymannuronic acid derivative (PM-C18) was synthesized as nanocarrier modified with hydrophobic oleyl amine. Its structure was confirmed by Fourier-transformed infrared spectrometry and nuclear magnetic resonance. To investigate its function, we developed tacrolimus (FK506) loaded nanoparticle by self-assembling PM-C18 and studied its drug loading, cytotoxicity and mechanism of in vitro release. Furthermore, we established a mouse model of allergic conjunctivitis (AC) to evaluate the efficacy of FK506 loaded PM-C18. The results indicated that PM-C18 carrier can encapsule FK506 with high drug loading (18%) and average particle size of 110.34±1.6nm. The release mechanism was diffusion initially followed a lasting release induced by swelling and collapse of PM-C18. One-week treatment with FK506 loaded PM-C18 efficiently relieved the symptoms of AC, which indicated it could serve as a potential ophthalmic drug for patients with AC. Compared with FK506 ophthalmic suspension, FK506 loaded PM-C18 improved medication adherence. Most importantly, we developed a novel versatile nanomaterial of PM-C18 which could encapsule other active agents for more applications.

Injectable alginate-microencapsulated canine adipose tissue-derived mesenchymal stem cells for enhanced viable cell retention.

The purpose of this study was to establish an optimized protocol for the production of alginate-encapsulated canine adipose-derived mesenchymal stem cells (cASCs) and evaluate their suitability for clinical use, including viability, proliferation and in vivo cell retention. Alginate microbeads were formed by vibrational technology and the production of injectable microbeads was performed using various parameters with standard methodology. Microbead toxicity was tested in an animal model. Encapsulated cASCs were evaluated for viability and proliferation in vitro. HEK-293 cells, with or without microencapsulation, were injected into the subcutaneous tissue of mice and were tracked using in vivo bioluminescent imaging to evaluate the retention of transplanted cells. The optimized injectable microbeads were of uniform size and approximately 250 µm in diameter. There was no strong evidence of in vivo toxicity for the alginate beads. The cells remained viable after encapsulation, and there was evidence of in vitro proliferation within the microcapsules. In vivo bioluminescent imaging showed that alginate encapsulation improved the retention of transplanted cells and the encapsulated cells remained viable in vivo for 7 days. Encapsulation enhances the retention of viable cells in vivo and might represent a potential strategy to increase the therapeutic potency and efficacy of stem cells.

Evaluation of alginate hydrogel cytotoxicity on three-dimensional culture of type A spermatogonial stem cells.

The culture of spermatogonial cells for future transplantation, based on the specific biology of these cells is important and necessary. Recently, the use of scaffolds especially alginate for culturing stem cells has been the focus of many researchers. The aim of this study was to evaluate the cytotoxicity of alginate hydrogels to cultures of type A spermatogonial stem cells. Spermatogonial stem cells of 6day-old immature mice were isolated by surgery; thereafter, the cells were purified by MACS using antibodies against thy-1 and C-kit and cultured on a layer of laminin. After purification, spermatogonial stem cells were encapsulated in alginate hydrogels. After one month of encapsulation and culture in DMEM culture medium containing 10ng/ml GDNF, cells were removed from hydrogel and were examined for viability, cell morphology and structure, cytotoxicity and expression of apoptosis genes Fas, P53, Bax, Bcl2, Caspase3 by staining with trypan blue, scanning electron microscopy, LDH test, and Real time PCR, respectively. The encapsulation did not change the morphology and viability of spermatogonial stem cells. Investigations showed that spermatogonial stem cells preserve by the high viability (74.08%) and cytotoxicity of alginate hydrogel was estimated to be 5%. Expression of Fas gene increased in main group compared with the control group, and expression of Bax and P53 was reduced in main group compared with the control group. Expression of Bcl2 and Caspase3 genes did not show any significant difference between the main group and the control group. Considering the lack of cytotoxicity and antioxidant properties of alginate hydrogel scaffold and high viability of cells, this three-dimensional scaffold is applicable for culturing and encapsulation of spermatogonial stem cells.

In vitro heterogeneous degradation of alginate and its validation of different molecular weight on blood bio-compatibility.

In the present work, sodium alginate (ALG) was degraded by heterogeneous phase acid degradation. The molecular weight distribution of ALG after degradation was close to homogenization. Then the blood bio-compatibility of ALG with different molecular weights (ALG-0h 50,075, ALG-0.5h 20,680, ALG-2h 13,170 and ALG-96h 1170 kDa) was evaluated in vitro and vivo. The human umbilical vein endothelial cells were used to assess the cytotoxicity of ALGs, ALG-0.5h and ALG-2h exhibited greater increment in percentage of cell viability comparing with ALG-0h and ALG-96h. With increasing of molecular weight of ALG, the blood clotting time was shortened and the hemolysis rate was slightly decreased. The different degree aggregation of red blood cells (RBCs) was observed in the ALG with different molecular groups and ALG-0h caused a severe aggregation of RBCs. Hematology analysis in vivo behavior after intraperitoneal (i.p.) injection indicated ALG-0h could cause blood solidification. Above results provided a reference for molecular weight selection in different applications.

Effects of alginate inclusion on the vector properties of chitosan-based nanoparticles.

Chitosan nanoparticles have shown considerable promise as gene vectors but do not mediate transfection with satisfactory efficiency. To improve upon the transfection efficiency of chitosan, we approached the development of alginate-chitosan nanoparticles with the goals of maintaining low toxicity and biocompatibility. Through ionic gelation, particles were formed with a mean Z-average diameter of 157 nm and a zeta potential of +32 mV. Competition binding assays indicated that the presence of alginate reduces the strength of interaction between chitosan and DNA, contributing to improved transfection. Cell viability assays indicated that nanoparticles exhibit the same low toxicity as chitosan, and significantly reduced toxicity compared to a commercial liposome formulation. As well, complexation with nanoparticles maintained DNA integrity and protected it from nuclease degradation better than chitosan alone. Alginate-chitosan nanoparticles were able to mediate transfection of 293T cells four times that achieved by chitosan nanoparticles; at 48 h, the transfection efficiency was as high as with Lipofectamine, with significantly reduced cytotoxicity. Overall, alginate inclusion improved the vector properties of chitosan-based nanoparticles, demonstrating superior transfection ability while maintaining biocompatibility and low toxicity.

Rose bengal and lissamine green inhibit detection of herpes simplex virus by PCR.

PURPOSE: To determine whether rose bengal and lissamine green affect polymerase chain reaction (PCR) detection of herpes simplex virus (HSV). DESIGN: Laboratory investigation. METHODS: Diagnostic corneal scrapings were evaluated for PCR inhibitory activity. Dacron swabs inoculated with rose bengal and lissamine green were processed as clinical samples, inoculated with control HSV, varicella zoster (VZV), cytomegalovirus (CMV), and toxoplasma DNA and prepared for PCR. The effects of calcium alginate and cotton swabs were also evaluated. RESULTS: Rose bengal, lissamine green, and calcium alginate not only inhibit PCR detection of HSV DNA, but also detection of VZV, CMV, and toxoplasma DNA. This inhibition could be overcome by serial dilution and by DNA purification of the sample before PCR. CONCLUSIONS: Rose bengal, lissamine green, and calcium alginate can inhibit PCR detection of HSV DNA. Clinical scrapings to be sent for PCR diagnostic testing should be taken before instillation of rose bengal or lissamine green.