Engineered Nanoparticles for Drug Delivery in Cancer Therapy *
Valerio Voliani in Nanomaterials and Neoplasms, 2021
The variation in pH value associated with a pathological situation such as cancer or inflammation has been extensively used to trigger the release of a drug into a specific organ (e.g., gastrointestinal tract or vagina) or intracellular compartment (e.g., endosome or lysosome) [70e]. Many anticancer drug delivery systems have exploited the difference in pH values existing between healthy tissues (ca. 7.4) and the extracellular environment of solid tumors (6.5–6.8). One approach is to use polymers with functional groups that can alter the density of charges in response to pH variation as the nanoparticle carriers. Notable examples include poly(acryl amide) (PAAm), poly(acrylic acid) (PAA), poly(methacrylic acid) (PMAA), poly(methyl acrylate) (PMA), poly(diethylaminoethyl methacrylate) (PDEAEMA), and poly(dimethylaminoethyl methacrylate) (PDMAEMA). With the use of these polymers, the structure and hydrophobicity of the nanoparticle carriers can change as a result of protonation or deprotonation [93].
Occupational nail diseases
Archana Singal, Shekhar Neema, Piyush Kumar in Nail Disorders, 2019
Amongst acrylics, the methacrylate and acrylate compounds are found in plastic glass for aircraft, paints, coatings, and printing inks, as well as in dentistry. Also, acrylates have a broad area of application in various products, such as the manufacture of dental prostheses and tooth fillings; printing colors; lacquers; paints; orthopedic prostheses and splints; soft contact lenses; histological preparations; floor waxes; floor coatings; surface treatments of leather, textiles, and paper products; nail cosmetics; and as glues, sealants, and adhesives.14 Nail cosmetics are obviously important allergens of the nail region. Usually, the dorsal aspects of some of the fingers and paronychial tissue, face, and the eyelids may begin to show an ACD.15 Thumb and index or middle finger of left hand of manicurists, who are constantly exposed to acrylates may also show ACD.16 Recently, in a study of 66 patients allergic to some acrylic monomer, the most commonly positive allergens were the methacrylates: ethylene glycol dimethacrylate (EGDMA), 2-hydroxyethyl methacrylate 2-HEMA and 2-hydroxypropyl methacrylate (2-HPMA), and the acrylates diethylene glycol diacrylate (DEGDA), and triethylene glycol diacrylate (TREGDA). The three methacrylates were positive in most patients exposed to dental products, glues, or artificial nails, and DEGDA was an important allergen in patients exposed to acrylates in printing work and in the manufacture of UV-cured paints. The patterns of concomitant reactions imply that methacrylates might induce cross-reactivity to acrylates, whereas acrylates do not usually induce sensitization to methacrylates.17
Glove Selection for Work with Acrylates Including Those Cured by Ultraviolet, Visible Light, or Electron Beam
Robert N. Phalen, Howard I. Maibach in Protective Gloves for Occupational Use, 2023
Acrylates refer to a class of acrylic acids (Figure 23.1), and their esters are defined by a carboxylic acid group bound to a carbon–carbon double bond (vinyl group), which is involved in polymerization and the formation of plastics. Acrylates can be divided into two broad categories of products. The first category is resinous-type chemicals that give the basic properties to the final industrial application. These synthetic molecules, which generally are of medium-to-high viscosity (typically ranging from syrupy to nearly solid or purely solids), are referred to as oligomers in industry. The second category consists of reactive diluents that co-react with the oligomers into the final polymeric network upon curing. They are typically referred to as monomers or MFAs (multifunctional acrylates) in industry. Their viscosity ranges from watery to more viscous, but still easily pourable liquids. Although these names are not chemically correct, we use the terms oligomer and monomer as described above throughout this chapter.Acrylic acid.The figure shows the chemical structure for acrylic acid with a carboxylic acid group (–COOH) bound to a carbon-carbon double bond (C=C) or vinyl group.
Methyl methacrylate and respiratory sensitisation: a comprehensive review
Published in Critical Reviews in Toxicology, 2022
Mark A. Pemberton, Ian Kimber
There was low confidence in the other clinical evidence (case studies, national surveillance data and SIC tests) for a combination of overlapping reasons. One of the primary weaknesses in these data is the lack of a comprehensive worker exposure history on which to base identification of the causative agent(s). In many cases there is clear evidence of selection and reporting bias reflecting a priori conclusion of causation by MMA. The characteristic smell of MMA and other meth(acrylates)may play a significant role in this respect. In some cases, this was further compounded by imprecision in the description of the chemistry involved and the clustering of acrylates, methacrylates and cyanoacrylates, without regard to their very different physical and chemical properties, and biological reactivity. In this respect, ECHA R.7a and clinicians (Shofer et al. 2006; Parhar et al. 2011; de Olim et al. 2015; Vandenplas et al. 2014, 2017) highlight the importance of making accurate exposure assessments both in the workplace and during SIC. Failure to follow this guidance prohibits any level of confidence in the assertion of a work-related pattern of disease causally related to a specific substance(s) and exclusion of non-specific irritation from SIC tests.
Development and evaluation of a drug-in-adhesive transdermal delivery system for delivery of olanzapine
Published in Expert Opinion on Drug Delivery, 2022
Deepal Vora, Ajay K. Banga
We aimed to obtain a similar coat weight for TDS with all three adhesives to understand the effect of adhesive matrix on the delivery of OZP across skin. The results of characterization studies of acrylate systems showed more shear strength than the other two, indicating acrylate adhesive-based systems are less prone to cold flow behavior. On the other hand, a low peel adhesion force for PIB systems indicated the ease of removing these systems due to a comparatively lower peel force required. Silicone systems showed the highest tack properties such as absolute force, positive area, and separation distance, demonstrating most adhesion properties. In addition to the above-discussed characterizations, the casted patches were stored at room temperature and observed for phase separation, residue on release liner after peeling, contraction/shrinkage of the film, edge lifting, tunneling, and ease of peeling off the patch applied on the skin model, as well as any residue on skin after removal of the patches [27,28]. IVPT studies using all three drug-in-adhesive TDS indicated successful delivery of OZP for 3 days. However, the amount of OZP delivered only from PIB suspension-based TDS met the desired target delivery.
An overview of polyallylamine applications in gene delivery
Published in Pharmaceutical Development and Technology, 2022
Leila Gholami, Asma Mahmoudi, Reza Kazemi Oskuee, Bizhan Malaekeh-Nikouei
For PAA modification, a series of studies was performed by our research group with the aim of increasing hydrophobicity of the polymer backbone to obtain more referable results regarding toxicity and transfection. In 2014, Oskuee and his research group modified PAA polymer in two molecular weights of 15 and 65 KD with alkane derivatives to develop a more practical carrier. The study results showed that the bromoalkane substitution in either percentage of 30 or 50 was more effective in transfection evaluation, and the most decreased cytotoxicity was reported in C/P ratio of 2 (Kazemi Oskuee et al. 2015). In 2015, an acrylate chain with different lengths was utilized to prepare a set of compounds with different degrees of hydrophobicity. The outcome of the study revealed that acrylate grafting lessens the polymer’s ability for DNA condensation, but it was acceptable for gene delivery assay. The most acceptable transfection results were achieved with the hexane acrylate chain, and increase in metabolic activity was attained by 30% and 50% grafting. In comparison with two molecular weights of polymer, the lower one with a higher percentage of hydrophobic chain modification was more efficient in cellular evaluation (Kazemi Oskuee et al. 2015).
Related Knowledge Centers
- Acrylic Acid
- Ester
- Salt
- Conjugate
- Methyl Acrylate
- Vinyl Group
- Bifunctional
- Ethyl Acrylate
- 2-Ethylhexyl Acrylate
- Butyl Acrylate