Development of emulsion-filled calcium alginate gels for thermoresponsive release of flavor in plant-based meat analogs.

We developed emulsion-filled calcium alginate gels (EF-CAG) as a novel thermoresponsive carrier for plant-based meat analogs (PBMA), designed to mimic the cooking-induced flavor release of real meat. Optimized to maximize flavor release upon heating, EF-CAG demonstrated a thermoresponsive release of 51% with a notable size reduction. Initial release profiles varied between media; a burst release of 43% occurred in water within the first 5 min, while <1% was released in air. EF-CAG consistently increased flavor release in PBMA during cooking, without adversely affecting appearance or flavor stability, maintaining flavor retention at 4 °C for 10 days. The sensory evaluation confirmed that EF-CAG successfully masked the beef flavor before cooking and enhanced its release afterward. Our findings suggest that EF-CAG can be effectively used as a flavoring agent for PBMA, offering similar flavor attributes to real meat during cooking.

A more natural follicle culture system: Detailed steps of In Vitro 3D follicle culture with alginate gel.

Follicle culture is a process of dividing follicle unit structures from ovaries for continued culture in vitro in an incubator, which simulates the in vivo environment. Alginate gel is the most stable and most convenient 3D material currently used in follicle culture. We performed in vitro follicle culture following the standard operating procedure recommended by the Follicle Handbook and we have summarized our experience and skills in details. Through several experiments, we found only follicles tightly surrounded by theca cells can grow healthily until the preovulatory stage. In addition, the hardness of alginate gel is crucial for constructing the 3D culture system, and selecting appropriate tools can reduce damage to the alginate gel and shorten the time follicles are exposed to room temperature. Our detailed operation improves bioavailability and provides a more natural environment for the entire process of follicular growth.•Alginate gel is still the most suitable 3D material used for in vitro follicle culture.•Follicle integrity and the hardness of alginate gel are the keys for in vitro culture.•Detailed operation steps better protect the follicular microenvironment and improve bioavailability.

Assessment of Alginate Gel Films as the Orodispersible Dosage Form for Meloxicam.

The aim of this study was to obtain films based on sodium alginate (SA) for disintegration in the oral cavity. The films were prepared with a solvent-casting method, and meloxicam (MLX) as the active ingredient was suspended in a 3% sodium alginate solution. Two different solid-dosage-form additives containing different disintegrating agents, i.e., VIVAPUR 112® (MCC; JRS Pharma, Rosenberg, Germany) and Prosolve EASYtabs SP® (MIX; JRS Pharma, Rosenberg, Germany), were used, and four different combinations of drying time and temperature were tested. The influence of the used disintegrant on the properties of the ODFs (orodispersible films) was investigated. The obtained films were studied for their appearance, elasticity, mass uniformity, water content, meloxicam content and, finally, disintegration time, which was studied using two different methods. The films obtained with the solvent-casting method were flexible and homogeneous in terms of MLX content. Elasticity was slightly better when MIX was used as a disintegrating agent. However, these samples also revealed worse uniformity and mechanical durability. It was concluded that the best properties of the films were achieved using the mildest drying conditions. The type of the disintegrating agent had no effect on the amount of water remaining in the film after drying. The water content depended on the drying conditions. The disintegration time was not affected by the disintegrant type, but some differences were observed when various drying conditions were applied. However, regardless of the formulation type and manufacturing conditions, the analyzed films could not be classified as fast disintegrating films, as the disintegration time exceeded 30 s in all of the tested formulations.

A sodium alginate gel bead adsorbent doping with amidoxime-modified hydroxyapatite for the efficient adsorption of uranium.

In this work, the modified­sodium alginate gel beads were prepared by sol-gel method. Due to the presence of water channels in the sodium alginate gel bead, amidoxime groups and PO43- were exposed to the surface of the adsorbent to the maximum extent, resulting in the excellent adsorption capacity of modified­sodium alginate gel beads. The introduction of amidoxime-modified hydroxyapatite significantly improved the adsorption capacity and the adsorption rate of the gel beads. The adsorption capacity increased from 308.7 to 466.0 mg/g and the adsorption equilibrium time was shortened from 300 min to 120 min. The modified­sodium alginate gel bead possessed the advantages of short adsorption time, high adsorption efficiency and large adsorption capacity, which could be regarded as a potential adsorbent for uranium. Moreover, the uranium removal ability on the modified gel beads was mainly attributed to the Coulomb force between PO43- and uranium and the complexation between uranium and amidoxime groups. In summary, this work would provide a new idea for the modification and application of sodium alginate-based materials.

Slow-sculpting graphene oxide/alginate gel loaded with platelet-rich plasma to promote wound healing in rats.

Wounds, especially chronic wounds, have become an important problem that endangers human health. At present, there are many repair methods, and among them combines materials science and biology is one of the important repair methods. This study explored the preparation method, physicochemical properties, biological activity and safety of Platelet-Rich plasma (PRP)-loaded slow-sculpting graphene oxide (GO)/alginate gel, and applied it to acute full-thickness skin defect wounds in rats to observe its role in wound healing. The results show that the slow-sculpting GO/alginate gel has excellent plasticity and is suitable for a variety of irregularly shaped wounds. At the same time, its porous structure and water content can maintain the activity of platelets and their released growth factors in PRP, thereby promoting wound collagen synthesis and angiogenesis to accelerate wound healing. This indicates that the slow-sculpting GO/alginate gel is an excellent loading material for PRP, and the combination of the two may become one of the methods to promote wound repair.

Alginate Gel Encapsulated with Enzybiotics Cocktail Is Effective against Multispecies Biofilms.

The development of new and effective antibacterials for pharmaceutical or cosmetic skin care that have a low potential for the emergence and expansion of bacterial resistance is of high demand in scientific and applied research. Great hopes are placed on alternative agents such as bactericidal peptidoglycan hydrolases, depolymerases, etc. Enzybiotic-based preparations are being studied for the treatment of various infections and, among others, can be used as topical formulations and dressings with protein-polysaccharide complexes. Here, we investigate the antibiofilm properties of a novel enzybiotic cocktail of phage endolysin LysSi3 and bacteriocin lysostaphin, formulated in the alginate gel matrix and its ability to control the opportunistic skin-colonizing bacteria Staphylococcus aureus, Pseudomonas aeruginosa, and Klebsiella pneumoniae, as well as mixed-species biofilms. Our results propose that the application of SiL-gel affects different components of biofilm extracellular polymeric substances, disrupts the matrix, and eliminates the bacteria embedded in it. This composition is highly effective against biofilms composed of Gram-negative and Gram-positive species and does not possess significant cytotoxic effects. Our data form the basis for the development of antibacterial skin care products with a gentle but effective mode of action.

Assessment of calcium alginate gels as wall materials for encapsulation systems.

BACKGROUND: Calcium alginate gels are widely used to encapsulate active compounds. Some characteristic parameters of these gels are necessary to describe the release of active compounds through mechanistic mathematical models. In this work, transport and kinetics properties of calcium alginate gels were determined through simple experimental techniques. RESULTS: The weight-average molecular weight ( M ¯ w = 192 × 103 Da) and the fraction of residues of α-l-guluronic acid ( F G = 0.356) of sodium alginate were determined by capillary viscometry and 1 H-nuclear magnetic resonance at 25 °C, respectively. Considering the half egg-box model, both values were used to estimate the molecular weight of calcium alginate as M g = 2.02 × 105 Da. An effective diffusion coefficient of water ( D eff , w = 2.256 × 10-9 m2 s-1 ) in calcium alginate was determined using a diffusion cell at 37 °C. Finally, a kinetics constant of depolymerization ( k m = 9.72 × 10-9 m3 mol-1 s-1 ) of calcium alginate was obtained considering dissolution of calcium to a medium under intestinal conditions. CONCLUSION: The experimental techniques used are simple and easily reproducible. The obtained values may be useful in the design, production, and optimization of the alginate-based delivery systems that require specific release kinetics of the encapsulated active compounds. © 2023 Society of Chemical Industry.

Recent Trends in S. aureus and E. coli-Based Endometritis, and the Therapeutic Evaluation of Sodium Alginate-Based Antibiotics and Nanoparticles.

Postpartum infection of the uterus by pathogenic bacteria is exacerbated due to a lack of sufficient epidemiological studies and evidence-based therapeutics. Therefore, this study was planned to find the prevalence, risk factors, and drug-resistance profile of S. aureus and E. coli isolated from bovine endometritis and to evaluate the antibacterial potential of sodium alginate-based antibiotics and nanoparticles. The study revealed 34.21% S. aureus and 31.57% E. coli, whereas most of the assumed risk factors presented significant association in this study. S. aureus showed the highest resistance against fusidic acid (60%) and cefoxitin (50%), while the highest resistance in E. coli was found against fusidic acid (60%), gentamicin (60%), chloramphenicol (50%), and cefoxitin (50%). Tylosin coupled with MgO nanoparticles stabilized in sodium alginate gel (Tylo + MgO + gel) presented significantly lower minimum inhibitory concentration (MIC) against E. coli, showing 13.88 ± 4.51 µg/mL after 24 h incubation. On the other hand, gel-based preparations showed MIC as 31.25 ± 0 µg/mL (Tylo + gel + MgO) and 26.04 ± 9.02 µg/mL (Tylo + Gel) against S. aureus. Generally, the MICs of non-gel-based preparations were significantly higher against bacteria except ampicillin against S. aureus in this study. The toxicity analysis of MgO nanoparticles presented 20-80% mortality of snails against a wider range of 0.01 mg/mL-10 mg/mL. The histopathological parameters concluded MgO nanoparticles safe to use on off targets. The current study thus concludes the rise in antimicrobial resistance while the gel-based products appearing as effective antimicrobials with sufficient safety margins for off-targets. The study thus invites further investigation for the development of suitable and affordable modified therapeutics for better health and production of animals.

Remote Positioning of Spherical Alginate Ferrogels in a Fluid Flow by a Magnetic Field: Experimental and Computer Simulation.

This work belongs to the development of mechanical force-responsive drug delivery systems based on remote stimulation by an external magnetic field at the first stage, assisting the positioning of a ferrogel-based targeted delivery platform in a fluid flow. Magnetically active biopolymer beads were considered a prototype implant for the needs of replacement therapy and regenerative medicine. Spherical calcium alginate ferrogels (FGs)~2.4 mm in diameter, filled with a 12.6% weight fraction of magnetite particles of 200-300 nm in diameter, were synthesized. A detailed characterization of the physicochemical and magnetic properties of FGs was carried out, as were direct measurements of the field dependence of the attractive force for FG-beads. The hydrodynamic effects of the positioning of FG-beads in a fluid flow by a magnetic field were studied experimentally in a model vessel with a fluid stream. Experimental results were compared with the results of mathematical and computer modeling, showing reasonable agreement. The contributions of the hydrodynamic and magnetic forces acting on the FG-bead in a fluid flow were discussed. Obtained forces for a single ferrogel implant were as high as 0 to 10-4 N for the external field range of 0 to 35 kA/m, perfectly in the range of mechanical force stimuli in biological systems.

Separable alginate gel spheres encapsulated with La-Fe modified biochar for efficient adsorption of Sb(III) with high capacity.

Sb and its compounds have been widely used in various industrial applications. Therefore, the preparation of Sb adsorbents with easy recovery and excellent adsorption levels is an urgent problem that must be resolved. By calcining and treating La/Fe metal-organic frameworks (MOF) biochar as a precursor, a loaded La-Fe-modified water hyacinth biochar was synthesised and used as a filler to synthesise iron alginate composite gel spheres, MBC/algFe. Through a series of static adsorption experiments, the effects of different filler addition ratios, solution pH, reaction time, coexisting ions, and other factors on the adsorption of Sb(III) were investigated. According to the Langmuir model, the maximum adsorption capacity of MBC/algFe at 25 â„ƒ was 277.8 mg·g-1. The adsorption mechanism mainly involved hydrogen bonding and metal-organic complexation interactions.

Mechanism of wound repair in diabetic rats using nanosilver-free alginate dressing.

OBJECTIVE: Nanosilver-alginate dressing can effectively promote the healing of diabetic wounds in rats. However, due to the potential toxicity of nanosilver, its widespread application in hard-to-heal wound healing is limited. In the present study, the role and potential mechanism of nanosilver-free alginate gel (NSFAG) in the healing process of diabetic wounds were explored. METHOD: A diabetic rat skin wound model was established, and wounds were treated with saline (NC group), nanosilver gel (NSG group) or nanosilver-free alginate gel (NSFAG group) for seven consecutive days. RESULTS: NSFAG significantly promoted wound healing and increased the content of protein and hydroxyproline in granulation tissues, and was superior to NSG (p<0.05). Immunohistochemical analyses revealed that the skin wound tissue structure of the NSFAG group was intact, and the number of skin appendages in the dermis layer was significantly higher compared with the NC group and the NSG group (p<0.05). Western blot analysis found that the protein expression of the epidermal stem cell marker molecules CK19 and CK14 as well the proliferation marker of keratinocytes Ki67 in the NSFAG group was significantly higher compared with the NC group or NSG group (p<0.05). Additionally, the proliferation marker of keratinocytes Ki67 in the NSFAG group was significantly higher compared with the NC or NSG group (p<0.05). Immunofluorescence staining analyses indicated that the CK19- and CK14-positive cells were mainly distributed around the epidermis and the newly formed appendages in the NSFAG group, and this result was not observed in the NC or NSG groups. CONCLUSION: The present findings demonstrate that NSFAG can effectively accelerate wound healing in diabetic rats by promoting epidermal stem cell proliferation and differentiation into skin cells, as well as formation of granulation tissue, suggesting that it can be a potential dressing for diabetic wounds.

Alginate Gel-Based Carriers for Encapsulation of Carotenoids: On Challenges and Applications.

Sodium alginate is one of the most interesting and the most investigated and applied biopolymers due to its advantageous properties. Among them, easy, simple, mild, rapid, non-toxic gelation by divalent cations is the most important. In addition, it is abundant, low-cost, eco-friendly, bio-compatible, bio-adhesive, biodegradable, stable, etc. All those properties were systematically considered within this review. Carotenoids are functional components in the human diet with plenty of health benefits. However, their sensitivity to environmental and process stresses, chemical instability, easy oxidation, low water solubility, and bioavailability limit their food and pharmaceutical applications. Encapsulation may help in overcoming these limitations and within this review, the role of alginate-based encapsulation systems in improving the stability and bioavailability of carotenoids is explored. It may be concluded that all alginate-based systems increase carotenoid stability, but only those of micro- and nano-size, as well as emulsion-based, may improve their low bioaccessibility. In addition, the incorporation of other biopolymers may further improve encapsulation system properties. Furthermore, the main techniques for evaluating the encapsulation are briefly considered. This review critically and profoundly explains the role of alginates in improving the encapsulation process of carotenoids, suggesting the best alternatives for those systems. Moreover, it provides a comprehensive cover of recent advances in this field.

Separable calcium sulphate modified biochar gel beads for efficient cadmium removal from wastewater.

This study outlines the synthesis of a novel, cost-effective composite material comprising calcium sulphate-modified biochar (Ca-BC) cross-linked with polyethyleneimine (PEI) and sodium alginate (SA), which was subsequently transformed into gel beads (Ca-BC@PEI-SA). These beads were engineered to enable effective cadmium ion (Cd(II)) adsorption from wastewater. Batch adsorption experiments were conducted to evaluate the effects of pH, contact time, temperature, and coexisting ions on adsorption performance. The isotherms and kinetics in the adsorption process were investigated. The results indicated that the removal of Cd(II) by Ca-BC@PEI-SA adheres more closely to the Langmuir model, with maximum adsorption capacities of 138.44 mg/g (15 °C), 151.98 mg/g (25 °C), and 165.56 mg/g (35 °C) at different temperatures. The pseudo-secondary model fit well with Cd(II) adsorption kinetics, suggesting that the removal process was a monolayer process controlled by chemisorption. Moreover, the mechanical strength of the Ca-BC@PEI-SA gel beads allowed easy recovery and reduced secondary contamination. In addition, the adsorption capacity remained nearly constant after four cycles. The main Cd(II) adsorption mechanisms involved surface complexation, ion exchange, and cation-π-bonding interactions.

Tannic acid-assisted fabrication of antibacterial sodium alginate-based gel beads for the multifunctional adsorption of heavy metal ions and dyes.

The existence of heavy metals and dyes seriously affects the ecological environment and human safety. Antibacterial adsorption materials with the broad-spectrum removal of multiple pollutants are urgently required for water remediation. Herein, a sustainable and antibacterial sodium alginate (SA) gel bead adsorbent with honeycomb cellular architecture is developed by the biomimetic deposition polyphenolic tannic acid (TA) induced grafting diethylenetriamine (DETA) under mild conditions for efficient removal of Cr(VI) and dyes. Taking advantage of the catechol surface chemistry, TA occurring rapid polymerization with DETA monomers not only enhances the water resistance and thermal stability of the gel bead, but also introduces abundant polyphenolic functional groups and active adsorption sites. The multifunctional gel bead showed outstanding antibacterial activity against S. aureus (sterilization rates: 83.8 %) and E. coli (sterilization rates: 99.5 %). The maximum adsorption capacity of gel bead for Cr(VI) was 163.9 mg/g. Moreover, the removal efficiency of the gel bead for dyes of Safranine T and Rhodamine B was 89.5 % (maximum adsorption capacity: 537 mg/g) and 76.7 % (maximum adsorption capacity: 460.2 mg/g), respectively, indicating its excellent broad-spectrum adsorption performance for multiple pollutants. Therefore, TA-assisted fabrication of SA-based gel bead with excellent antibacterial property is a promising multifunctional adsorption material for practical water remediation.

Structural and mechanical analysis on mannuronate-rich alginate gels and xerogels beads based on Calcium, Copper and Zinc as crosslinkers.

Beads based on a mannuronate(M)-rich alginate (86 % M units) were prepared by adding the polysaccharide solution to a crosslinking bath containing different concentrations (0.5, 2 and 10 wt%) of XCl2 where X = Ca, Cu or Zn. Primarily focus was on Zn, due to its antioxidant, anti-inflammatory and anti-microbial capabilities. The beads were characterized by Field-Emission Scanning Electron Microscopy (FESEM), Fourier-Transform Infra-Red spectroscopy (FT-IR), Thermogravimetric Analysis (TGA), Small-Angle X-ray Scattering (SAXS) and compression tests. The crosslinking agent significantly influenced the properties of the resulting beads. Specifically, Ca-based beads exhibited a smoother surface, while Cu- and Zn-based beads appeared rougher. Interestingly, Zn-based beads displayed a core-shell structure. Young moduli ranged from 3500 and 7000 MPa, with the highest values observed for Zn-beads. SAXS investigation at 0.5 wt% XCl2 suggested increase in the densely packed domains amount in the order: Ca < Cu < Zn. Extended X-ray Absorption Fine Structure (EXAFS) showed that the coordination number was 4.3 ± 0.4 for Cu, and 4.0 ± 0.2 and 1.1 ± 0.1 for Zn in 0.5 wt% XCl2 alginate xerogels, in agreement with reported Density Functional Calculations on Cu2+- and Zn2+-MM complexes. The results from FT-IR, compositional analysis and EXAFS collectively suggested a bridging coordination for these systems.

Macroscopic Pattern Formation of Alginate Gels in a Two-Dimensional System.

Macroscopic spatial patterns were formed in calcium alginate gels when a drop of a calcium nitrate solution was placed on the center of a sodium alginate solution on a petri dish. These patterns have been classified into two groups. One is multi-concentric rings consisting of alternating cloudy and transparent areas observed around the center of petri dishes. The other is streaks extending to the edge of the petri dish, which are formed to surround the concentric bands between the concentric bands and the petri dish edge. We have attempted to understand the origins of the pattern formations using the properties of phase separation and gelation. The distance between two adjacent concentric rings was roughly proportional to the distance from where the calcium nitrate solution was dropped. The proportional factor p increased exponentially for the inverse of the absolute temperature of the preparation. The p also depended on the concentration of alginate. The pattern characteristics in the concentric pattern agreed with those in the Liesegang pattern. The paths of radial streaks were disturbed at high temperatures. The length of these streaks shortened with increasing alginate concentration. The characteristics of the streaks were similar to those of crack patterns resulting from inhomogeneous shrinkage during drying.

Biological treatment of perfluorooctanesulfonic acid (PFOS) using microbial capsules of a polysulfone membrane.

Perfluorooctanesulfonic acid (PFOS) is a persistent organic substance that has been extensively applied in many industries and causes severe, widespread adverse health impacts on humans and the environment. The development of an effective PFOS treatment method with affordable operational costs has been expected. This study proposes the biological treatment of PFOS using microbial capsules enclosing a PFOS-reducing microbial consortium. The objective of this study was to evaluate the performance of the polymeric membrane encapsulation technique for the biological removal of PFOS. First, a PFOS-reducing bacterial consortium, composed of Paracoccus (72%), Hyphomicrobium (24%), and Micromonosporaceae (4%), was enriched from activated sludge by acclimation and subsequent subculturing with PFOS containing media. The bacterial consortium was first immobilized in alginate gel beads, then enclosed in membrane capsules by coating the gel beads with a 5% or 10% polysulfone (PSf) membrane. The introduction of microbial membrane capsules could increase PFOS reduction to between 52% and 74% compared with free cell suspension, which reduced by 14% over three weeks. Microbial capsules coated with 10% PSf membrane demonstrated the highest PFOS reduction at 80% and physical stability for six weeks. Candidate metabolites including perfluorobutanoic acid (PFBA) and 3,3,3- trifluoropropionic acid were detected by FTMS, suggesting the possible biological degradation of PFOS. In microbial membrane capsules, the initial adsorption of PFOS on the shell membrane layer enhanced subsequent biosorption and biological degradation by PFOS-reducing bacteria immobilized in the core alginate gel beads. The 10%-PSf microbial capsules exhibited a thicker membrane layer with the fabric structure of a polymer network, which maintained longer physical stability than 5%-PSf microbial capsules. This outcome suggests the potential application of microbial membrane capsules to PFOS-contaminated water treatment.

Fabrication of an alginate-based ZhiNengCong gel showed an enhanced antiviral and plant growth promoting functions.

Tobacco mosaic disease is a worldwide viral disease that can cause huge economic losses. Plant immune inducers have become the main force in the prevention and treatment of viral disease own to their high efficiency and rapid effect. However, since tobacco mosaic disease can occur at any point in the plant growth cycle, a single application period cannot guarantee the completely management. In this study, an extract from Paecilomyces variotii named ZhiNengCong (ZNC), which can fight against tobacco mosaic disease with 65% control effect, and improve the promotion of tobacco stem girth, was selected from five commercial antiviral medicines, and a sustained release sodium alginate (Alg)-based ZNC (ZNC@Alg) was prepared by physical absorption. ZNC@Alg, who contains only 5 mg/mL ZNC, can release ZNC for 7 consecutive days, and displayed an enhanced effect in inducing the PAL-mediated salicylic acid signaling pathway activation to participate in the inhibition of green fluorescent protein (GFP)-tagged tobacco mosaic virus (TMV-GFP) infection, even after 7 days of the application. Notably, field experiments showed that the control effect of ZNC@Alg was up to 88%, which was significantly better than that of ZNC with the same concentration (10 µg per plant). In addition, ZNC@Alg exhibited a stronger growth-promoting effect than ZNC, which significantly increased the wet weight of tobacco. Taken together, we screened out a plant immune inducer ZNC that can effectively inhibit tobacco virus disease, and created ZNC@Alg with higher control effect and growth promotion effect, laying a foundation for effective field management of tobacco mosaic disease.

Swelling of Homogeneous Alginate Gels with Multi-Stimuli Sensitivity.

A new two-step method is suggested for the preparation of homogeneous alginate gels. In the first step, alginate chains are weakly bonded by Ca2+ ions in an aqueous solution with a low pH. In the next step, the gel is immersed into a strong solution of CaCl2 to finalize the cross-linking process. Homogeneous alginate gels preserve their integrity in aqueous solutions with a pH ranging from 2 to 7 and ionic strength in the interval from 0 to 0.2 M, at temperatures ranging from room temperature up to 50 °C, and can be used in biomedical applications. The immersion of these gels into aqueous solutions with low pH induces the partial breakage of ionic bonds between chains (treated as gel degradation). This degradation affects the equilibrium and transient swelling of homogeneous alginate gels and makes them sensitive to the history of loading and environmental conditions (pH, ionic strength and temperature of aqueous solutions). As sensitivity to the environmental stimuli is a characteristic feature of polymer networks connected by catch bonds, homogeneous alginate gels may serve as a simple model, mimicking the behavior of more sophisticated structures in living matter.

A novel technique of vagino-hysteroscopy using alginate gel interface: A proof of concept study.

OBJECTIVE: To compare the feasibility of vagino-hysteroscopy using alginate gel Interface (VAGI) with conventional vaginoscopic hysteroscopy (CVH). METHODS: Thirty women undergoing diagnostic vagino-hysteroscopy were randomly allocated into Group I (VAGI): Alginate occluder was used at introitus to facilitate hydrodistension during hysteroscopy; or Group II: Underwent no-touch hysteroscopy. Primary outcome was feasibility, defined as successful visualization of uterine cavity. Secondary outcomes included operative time, hydrostatic pressures for optimum visualization, pain experienced by patient on visual analog scale, maneuverability and surgeon satisfaction. Data analysis was performed using χ2 and Fisher exact tests for qualitative variables and Student t test for quantitative variables. RESULTS: VAGI was significantly better than CVH (80% vs. 33.3%; relative risk 8, P = 0.025). With VAGI, optimum visualization was achieved at significantly lower pressures at all levels (vagina, P = 0.034; cervix, P = 0.01; uterus, P < 0.001), in less time (P = 0.007), and using less irrigation fluid (P < 0.001). Surgeon satisfaction was significantly higher for VAGI (P = 0.009). Subgroup analysis showed higher likelihood of success of VAGI in women who were premenopausal (P = 0.015), younger than 45 years (P = 0.024), and had a history of vaginal birth (P = 0.03). CONCLUSIONS: VAGI is quicker to perform and provides optimum visualization at much lower pressures than CVH. Use of alginate is patient friendly and yields higher surgeon satisfaction rate.