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Journal of AOAC International Sep 2021Recently, functional polymers have attracted significant attention in the areas of pharmaceuticals and biomedical applications, so it is important to develop simple...
BACKGROUND
Recently, functional polymers have attracted significant attention in the areas of pharmaceuticals and biomedical applications, so it is important to develop simple techniques to analyze functional polymers in their pharmaceutical dosage forms.
OBJECTIVE
Three simple, accurate, and sensitive UV spectrophotometric methods have been developed and validated for determination of polyvinyl pyrrolidone (PVP) in the presence of benzalkonium chloride (BZ) and sodium lactate in ternary mixtures.
METHOD
Method A is a derivative ratio spectra zero-crossing (DRSZ) method which measures PVP peak amplitude at 303.1 nm. Method B is a double divisor ratio derivative (DDRD), used for determination of both PVP and BZ in the presence of sodium lactate at 272.6 and 271.5 nm, respectively. Method C is a double divisor ratio derivative-ratio difference spectrophotometric method (DDRD-RDSM), a new and hybrid method of double divisor and ratio difference that hasn't been applied before. It measures peak amplitude difference of the ratio spectra at ΔP278 - 252.4 and ΔP260.9 - 213 for PVP and BZ, respectively.
RESULTS
Linear ranges for PVP (5.00-35.00, 10.00-40.00, and 10.00-40.00 µg/mL) was obtained by using DRSZ, DDRD, and DDRD-RDSM, respectively. While the linear range for BZ (5.00-60 µg/mL) was obtained by using both DDRD and DDRD-RDSM.
CONCLUSIONS
All results were statistically compared with reported methods. No significant differences were observed. The developed methods were applied to the analysis of the investigated drugs in pure and pharmaceutical dosage forms.
HIGHLIGHTS
The proposed methods are of great value, improving the efficiency of routine analysis of PVP and BZ in their pharmaceutical dosage forms.
Topics: Pharmaceutical Preparations; Polyvinyls; Povidone; Spectrophotometry
PubMed: 33484245
DOI: 10.1093/jaoacint/qsaa177 -
Der Radiologe Apr 2020Various materials are currently available for the endovascular treatment of aneurysms. The choice of material depends on the location and configuration of the aneurysm.... (Review)
Review
Various materials are currently available for the endovascular treatment of aneurysms. The choice of material depends on the location and configuration of the aneurysm. To ensure optimal aneurysm treatment, the filling material must incorporate the aneurysm and isolate it from the parent vessel by forming an endothelial layer and neointima proliferation along the aneurysm neck. As a result, the aneurysm can be permanently isolated from the blood flow and the weakened vessel wall can be stabilized in the long term in order to prevent subsequent rupture. Bare metal coils are currently most commonly used. In recent years, liquid embolic agents have increasingly been developed for the endovascular treatment of aneurysms. One of the reasons is that the injected fluid completely fills the aneurysm lumen, so there is no gap between the filling material and the aneurysm wall, regardless of the shape of the aneurysm. Most of the preclinical and clinical studies are available for Onyx. In particular for the treatment of mycotic aneurysms and distal aneurysms of the posterior circulation, liquid embolization with Onyx has already proven to be a possible, effective treatment method.
Topics: Aneurysm; Dimethyl Sulfoxide; Embolization, Therapeutic; Humans; Polyvinyls; Treatment Outcome
PubMed: 32157321
DOI: 10.1007/s00117-020-00668-4 -
Chemical Communications (Cambridge,... Nov 2022Methyl vinyl glycolate (MVG) can be obtained by acid-catalyzed conversion of C4 and C6 sugars. Applications of MVG in polymers are so far limited to its use as...
Methyl vinyl glycolate (MVG) can be obtained by acid-catalyzed conversion of C4 and C6 sugars. Applications of MVG in polymers are so far limited to its use as co-monomer for poly(lactic acid) and as crosslinking agent. In this work, hydroformylation and methoxycarbonylation of MVG were investigated to produce novel bifunctional monomers. Polyesters with high renewable-atom content were successfully prepared and characterized.
Topics: Polyesters; Glycolates; Polymers; Polyvinyl Chloride
PubMed: 36342084
DOI: 10.1039/d2cc05609g -
Journal of Food Biochemistry Apr 2021Mechanical damage and microbial infestation were critical issues during strawberry transportation. This study prepared a modified polyvinyl formal (PVFM)...
Mechanical damage and microbial infestation were critical issues during strawberry transportation. This study prepared a modified polyvinyl formal (PVFM) vibration-damping material and investigated its application in strawberry transportation. This modified PVFM was primarily composed of polyvinyl alcohol, starch, formaldehyde, and allyl isothiocyanate. Our results showed that the modified PVFM had good vibration-damping and antifungal properties with 0.137 g/m of density, a water absorption ratio value of 6.24, 278 Pa of tensile strength, 3.86 Pa of elastic modulus, a buffer coefficient of 0.318, and antifungal rates of 68.8% and 80.6% against Bacillus anthracis and Botrytis cinerea, respectively. Moreover, this modified PVFM could enhance the storage life of strawberry by improving PAL activity from 376 to 3,125 U/g, inhibiting POD activity with a maximum value of 3.1 U/g, and decreasing CAT activity from 324 to 35 U/g. The modified PVFM presented a good vibration-damping capacity and the potential to extend strawberry shelf life. PRACTICAL APPLICATIONS: Berry fruits were vulnerable to mechanical damage caused by vibration during transportation, resulting in quality deterioration, rot, and aging. In this study, modified polyvinyl formal (PVFM) was prepared and was of low density and displayed good mechanical, vibration-damping, and antifungal properties. The modified PVFM could improve the storage life of strawberry. Thus, the modified PVFM could have potential application in berry fruits transportation.
Topics: Botrytis; Fragaria; Polyvinyls; Vibration
PubMed: 33569826
DOI: 10.1111/jfbc.13647 -
Journal of Biomedical Materials... Jan 2023Electroactive smart materials play an important role for tissue regenerative applications. Poly(vinylidene fluoride) (PVDF) is a specific subtype of piezoelectric...
Electroactive smart materials play an important role for tissue regenerative applications. Poly(vinylidene fluoride) (PVDF) is a specific subtype of piezoelectric electroactive material that generates electrical potential upon mechanical stimulation. This work focuses on the application of piezoelectric PVDF films for neural differentiation. Human neural precursor cells (hNPCs) are cultured on piezoelectric poled and non-poled β-PVDF films with or without a pre-coating step of poly-d-lysine and laminin (PDL/L). Subsequently, hNPCs differentiation into the neuronal lineage is assessed (MAP2 and DCX ) under static or dynamic (piezoelectric stimulation) culture conditions. The results demonstrate that poled and coated β-PVDF films induce neuronal differentiation under static culture conditions which is further enhanced with mechanical stimulation. In silico calculations of the electrostatic potential of different domains of laminin, highlight the high polarity of those domains, which shows a clear preference to interact with the varying surface electric field of the piezoelectric material under mechanical stimulation. These interactions might explain the higher neuronal differentiation induced by poled β-PVDF films pre-coated with PDL/L under dynamic conditions. Our results suggest that electromechanical stimuli, such as the ones induced by piezoelectric β-PVDF films, are suitable to promote neuronal differentiation and hold great promise for the development of neuroregenerative therapies.
Topics: Humans; Electricity; Laminin; Neural Stem Cells; Polyvinyls; Electric Stimulation
PubMed: 36069387
DOI: 10.1002/jbm.a.37443 -
Molecules (Basel, Switzerland) Sep 2022The development of targeted therapies for wound repair is knowing a growing interest due to the increasing aging of the population and the incidence of chronic...
The development of targeted therapies for wound repair is knowing a growing interest due to the increasing aging of the population and the incidence of chronic pathologies, mainly pressure ulcers. Among molecules recruiting cell populations and promoting the formation of new vital tissue, sodium mesoglycan (MSG) has been proven to be effective in wound healing. In this work, MSG impregnation of polymer matrices has been attempted by a supercritical carbon dioxide-based process. Polymeric matrices are composed of polycaprolactone blends, where water-soluble polymers, polyethylene glycol, polyvinyl pyrrolidone, gelatin, and thermoplastic starch, have been employed to modulate the MSG release, making the devices potentially suitable for topical administrations. Two different techniques have been used to obtain the films: the first one is compression molding, producing compact and continuous structures, and the second one is electrospinning, producing membrane-like designs. A higher amount of MSG can be loaded into the polymeric matrix in the membrane-like structures since, in these films, the impregnation process is faster than in the case of compression molded films, where the carbon dioxide has firstly diffused and then released the active molecule. The type of water-soluble polymer influences the drug release rate: the blend polycaprolactone-gelatin gives a prolonged release potentially suitable for topical administration.
Topics: Carbon Dioxide; Gelatin; Glycosaminoglycans; Polyesters; Polyethylene Glycols; Polymers; Polyvinyls; Povidone; Sodium; Starch; Water
PubMed: 36144536
DOI: 10.3390/molecules27185800 -
International Journal of Biological... Jan 2023Despite many technical challenges in the development of safe and environmentally friendly food packaging paper materials with excellent water and oil resistance using...
Water and oil-resistant paper materials based on sodium alginate/hydroxypropyl methylcellulose/polyvinyl butyral/nano-silica with biodegradable and high barrier properties.
Despite many technical challenges in the development of safe and environmentally friendly food packaging paper materials with excellent water and oil resistance using simple methods, producing paper-based functional materials using bio-based polymers is currently an important topic in the food packaging industry. In this study, novel water and oil-resistant coatings for the paper were developed through the combination of sodium alginate (SA), hydroxypropyl methylcellulose (HPMC), polyvinyl butyral (PVB), and hydrophobic silica nanoparticles (HSNPs). To impart oil-repellency to paper, SA and HPMC were first mixed uniformly and coated on the base paper, which was pre-treated with calcium chloride solution. A compact and tough coating layer was formed on paper due to the hydrogen bonding between SA and HPMC molecules, and the crosslinking between SA and Ca ions in the base paper. High water resistance of the paper was achieved through the coating of PVB and HSNPs on top of the coating of SA/HPMC. The final coated paper demonstrated outstanding oil resistance (kit rating: 12/12), water resistance (Cobb value: 4.23 g/m), low water vapor transmission rate (100 g/m·24 h), and improved mechanical properties. This fluorine-free, and biodegradable barrier paper will find excellent applications in the food packaging industry.
Topics: Hypromellose Derivatives; Alginates; Polyvinyls; Food Packaging
PubMed: 36252631
DOI: 10.1016/j.ijbiomac.2022.10.104 -
AAPS PharmSciTech Nov 2023Nimodipine (NMD) is a 1,4-dihydropyridine calcium antagonist that is effective in the prevention and treatment of cerebral arterial vasospasm and cerebral ischemic...
Nimodipine (NMD) is a 1,4-dihydropyridine calcium antagonist that is effective in the prevention and treatment of cerebral arterial vasospasm and cerebral ischemic injury caused by subarachnoid hemorrhage. Since the drug itself is highly insoluble in water and has low oral bioavailability, while injectable formulations may cause pain and inflammation, the blood-brain barrier (BBB) prevents the effective delivery of therapeutic agents to the brain tissue. Therefore, in the present study, NMD liposomes were prepared by ethanol injection and innovatively lyophilised and loaded into temperature-sensitive in situ gels for intranasal administration as sprays to deliver drugs to brain tissues bypassing the blood-brain barrier. The optimal gel formulation was obtained by screening in which liposomes were divided into lecithin, cholesterol, and NMD in the ratio of 40:10: 1; Pluronic P407, Pluronic P188, Tween 80, polyvinyl ketone and ethyl nipagin in the ratio of (180:20:3:1:1); Pluronic P407, Pluronic P188, Tween 80, polyvinyl ketone, and ethyl nipagin in the ratio of (180:20:3:1:1). The prepared flow gel can form a solidified gel after a temperature of 31.07-32.07°C and a time of 58.51-59.89 s. Meanwhile, the NMD liposome gel formulation achieved sustained release over 56 h. The pharmacokinetic results of the developed NMD liposomal temperature-sensitive in situ gel and NMD temperature-sensitive in situ gel showed that liposomal nasal mucosal in situ gel is a more effective brain-targeted drug delivery system for NMD.
Topics: Liposomes; Nimodipine; Poloxamer; Polysorbates; Polyvinyls; Drug Delivery Systems; Administration, Intranasal; Gels; Nasal Mucosa; Temperature; Ketones
PubMed: 37973673
DOI: 10.1208/s12249-023-02679-5 -
Translational Vision Science &... Apr 2020This study compared intraocular toxicity of intravitreally injected povidone-iodine (PI) and polyvinyl alcohol-iodine (PAI) in rabbits.
PURPOSE
This study compared intraocular toxicity of intravitreally injected povidone-iodine (PI) and polyvinyl alcohol-iodine (PAI) in rabbits.
METHODS
In each rabbit, 0.1 mL of PI or PAI solution was injected intravitreally into one eye and saline was injected into the other. PI was tested at available iodine concentrations of 0.05%, 0.1%, 0.2%, and 0.5%, and PAI at 0.05%, 0.1%, and 0.2% (n = 6 each). Electroretinograms were recorded before injection and 1, 7, and 14 days after injection. Pathological examinations of eyeballs were performed on day 15.
RESULTS
Mean b-/a-wave ratios of the electroretinograms did not change in eyes injected with 0.05%, 0.1%, or 0.2% PI (PI-0.05, PI-0.1, and PI-0.2, respectively) or in eyes injected with 0.05% or 0.1% PAI (PAI-0.05 and PAI-0.1, respectively) compared to saline-injected eyes, but was transiently impaired on day 1 in PAI-0.2 eyes. Histopathologically, no retinal abnormalities were observed in PI-0.05, PAI-0.05, or PAI-0.1 eyes. One PI-0.1 eye first showed localized inflammatory cell infiltration in the inferior retinal region. Two PI-0.2 eyes and one PAI-0.2 eye had retinal degeneration and inflammatory cell infiltration. In the PI-0.5 group, extensive inflammatory cell infiltration was observed in six eyes and inferior retinal detachment in five eyes.
CONCLUSIONS
PI and PAI have equivalent retinal toxicity profiles, and retinal toxicity first affects the inner retinal layer in the inferior region. The highest non-retinotoxic vitreous concentration is 0.0033% available iodine from intravitreal injection of PI or PAI containing 0.05% available iodine.
TRANSLATIONAL RELEVANCE
Low concentrations of PI or PAI can be used to wash the ocular surface during surgery or intravitreal injection to prevent endophthalmitis.
Topics: Animals; Intravitreal Injections; Iodine; Polyvinyl Alcohol; Povidone-Iodine; Rabbits; Vitreous Body
PubMed: 32821477
DOI: 10.1167/tvst.9.5.5 -
ACS Nano Jul 2019Soft and stretchable electrodes are essential components for skin-tight wearable devices, which can provide comfortable, unobtrusive, and accurate physiological...
Soft and stretchable electrodes are essential components for skin-tight wearable devices, which can provide comfortable, unobtrusive, and accurate physiological monitoring and physical sensing for applications such as healthcare, medical treatment, and human-machine interfaces. Metal-elastomer nanocomposites are a promising approach, enabling high conductivity and stretchability derived from metallic conduction and percolation networks of metal nano/micro fillers. However, their practical application is still limited by their inferior cyclic stability and long-term durability. Here, we report on a highly durable nanofiber-reinforced metal-elastomer composite consisting of (i) metal fillers, (ii) an elastomeric binder matrix, and (iii) electrospun polyvinylidene fluoride nanofibers for enhancing both cyclic stability and conductivity. Embedded polyvinylidene fluoride (PVDF) nanofibers enhance the toughness and suppress the crack growth by providing a fiber reinforcing effect. Furthermore, the conductivity of nanofiber-reinforced elastic conductor is four times greater than the pristine material because the silver-rich layer is self-assembled on the top surface by a filtering effect. As a result, a stretchable electrode made from nanofiber-reinforced elastic conductors and wrinkled structures has both excellent cyclic durability and high conductivity and is stretchable up to 800%. The cyclic degradation () remains at 0.56 after 5000 stretching cycles (50% strain), whereas initial conductivity and sheet resistance are 9903 S cm and 0.047 Ω sq, respectively. By utilizing a highly conductive and durable elastic conductor as sensor electrodes and wirings, a skin-tight multimodal physiological sensing suit is demonstrated. Continuous long-term monitoring of electrocardiogram, electromyogram, and motions during weight-lifting exercises are successfully demonstrated without significant degradation of signal quality.
Topics: Elastomers; Electric Conductivity; Electrodes; Nanofibers; Particle Size; Polyvinyls; Silver; Surface Properties; Textiles; Wearable Electronic Devices
PubMed: 31244040
DOI: 10.1021/acsnano.9b02297