Public Health, Vol 2, Issue 1, Jan-Mar / Oral Biopsy in General Dental Practice: A DOI/ijmedph 2Dept of Oral Pathology & Microbiology. Oral Health for the Americas (“the Plan”) (Document CD47/14), adopted in through . Most country programs have integrated oral health care into. referred to as oral health indicators, and include dental caries experience, untreated dental decay, tooth removal FLUORIDATION OF WATER SUPPLIES.
In vivo, radiolabeled particles were mainly found in luminal content and also adsorbed onto the epithelium. However, histological evaluation revealed low uptake of particles by Peyer's patches. As a conclusion, this study provided a good correlation between in vitro and in vivo evaluation. These particles could be useful for oral sustained release and delivery of drugs to intestinal and colon epithelium. This is clearly an advantage for studying in vitro cell interaction over a prolonged time period.
Previously reported results in the literature using the same test for evaluation of cytotoxicity [21, 22] are in accordance with the trend that toxicity is correlated with the rate of polymer degradation. Surface-engineered nanoparticles for multiple ligand coupling. The design of surface-engineered nanoparticles for targeting to specific sites is a major challenge. To our knowledge, no study in the literature deals with ligand functionalization of biodegradable nanoparticles through biotin-avidin interactions.
With the aim of conceiving small-sized nanoparticles which can be easily functionalized with a variety of ligands or mixtures thereof, biotinylated and PEGylated biotin-poly ethylene glycol -poly epsilon-caprolactone B-PEG-PCL copolymers were synthesized and used to prepare nanoparticles of around nm. Avidin, followed by biotinylated wheat germ agglutinin as a model lectin, were coupled to their surface by taking advantage of the strong biotin-avidin complex formation.
This value was increased to 8. After further studies, the biotin-PEG-coated nanoparticles could be helpful tools for studying the interaction between cells and functionalized nanoparticles with various surface characteristics PEG layer density and thickness, ligand type and density. Such a model would allow the screening in a systematic manner of the effect of the physicochemical properties of the particles. Caco-2 cells derived from a colonic cancer cells has been tested for different types of particles and seems to be an interesting tool.
However, all the parameters for this model have not been fully characterized. Oral administration remains the most convenient way of delivering drugs.
Recent advances in biotechnology have produced highly potent new molecules such as peptides, proteins and nucleic acids. Due to their sensitivity to chemical and enzymatic hydrolysis as well as a poor cellular uptake, their oral bioavailability remains very low.
Despite sophisticated new delivery systems, the development of a satisfactory oral formulation remains a challenge. Among the possible strategies to improve the absorption of drugs, micro- and nanoparticles represent an exciting approach to enhance the uptake and transport of orally administered molecules.
Increasing attention has been paid to their potential use as carriers for peptide drugs for oral administration. This article reviews the most common manufacturing methods for polymeric particles and the physiology of particle absorption from the gastrointestinal GI tract. In a second part, the use of polymeric particulate systems to improve the oral absorption of insulin is discussed.
Polymeric particulates to improve oral bioavailability of peptide drugs. Influence of a non-ionic poloxamer surfactant, Pluronic F68, on protein release from poly methylidene malonate 2. We recently described a new microparticulate system based on poly methylidene malonate 2. This paper focuses on an in vitro evaluation of this system for oral administration. Degradation studies, achieved in simulated gastric and intestinal media, have shown that size distribution and polymer molecular weight were not modified over an 8-h incubation period, confirming that such microparticles are suitable for oral administration.
This release was attributed to the degradation of surface-bound protein, the distribution of which at the microparticle surface was confirmed by confocal microscopy. The addition of Pluronic F68 to the internal phase promoted-ovalbumin location inside the internal globules, leading to a diminished release in the same media. Therefore, a clear correlation was established between the modification of protein location within microparticles by Pluronic F68 and protection against degradation in simulated digestive media.
Poly ether ester amide Microspheres for Protein Delivery: Jul Macromol Biosci. The production of PEEA microspheres with potential as carriers for protein oral delivery is described. PEEAs with different hydrophilicity were synthesized and characterized. Experiments showed that an increase in copolymer hydrophilicity gave particles less prone to cell interaction.
BSA release profiles from PEEA microspheres demonstrated that an increase in polymer hydrophilicity was useful in limiting protein burst and modulating drug delivery rate by increasing PEEA degradability. Application and further development of chemical engineering principles for chemotherapy of cancer and other diseases.
This review defines chemotherapeutic engineering as an engineering discipline that applies and further develops chemical engineering principles, techniques and devices for chemotherapy of cancer and other diseases. It provides new challenges as well as new opportunities for chemical engineering. Chemical engineering has substantially changed the human civilization through its services and products to improve the quality of life for human being.
It is now time for chemical engineering to contribute to the most important aspect of the quality of life—human health care.
Cancer and cardiovascular diseases are the leading causes for deaths. Chemotherapy is one of the most important treatments currently available for cancer and other diseases such as cardiovascular diseases. The present status of chemotherapy is far from being satisfactory.
Its efficacy is limited and patients have to suffer from serious side effects, some of which are life-threatening. Chemotherapeutic engineering is emerging to help solving the problems in chemotherapy and to eventually develop an ideal way to conduct chemotherapy with the best efficacy and the least side effects. This review gives, from an engineering point of view, brief introductions to cancer and cancer treatment, chemotherapy and the problems involved in chemotherapy, and the possible roles of chemical engineering in solving the problems involved.
Progress in developing various controlled and targeted drug delivery systems is reviewed with an emphasis on nanoparticles of biodegradable polymers and lipid bilayer vesicles liposomes. Preparation, characterization, in vitro release, cell line experiments and animal testing of drug-loaded polymeric nanoparticles are described with paclitaxel as a prototype drug, which is one of the best anticancer drugs found in nature.
A novel drug delivery system, liposomes-in-microspheres, is used as an example for possible combinations of the existing polymer- and lipid-based delivery systems. Research of molecular interactions between the drug and the cell membrane is also reviewed, with the lipid monolayer at the air—water or oil—water interface and bilayer vesicles as models for the cell membrane. Finally, mathematical modeling in chemotherapeutic engineering is discussed with typical examples in the literature.
This review is a short introduction of chemotherapeutic engineering to chemical engineers, biomedical engineers, other engineers, clinical oncologists, and pharmaceutical scientists, who are interested in developing new dosage forms of drugs for chemotherapy of cancer and other diseases with the best efficacy and the least side effects. Bioadhesive characterization of poly methylidene malonate 2.
The efficacy of a drug delivery system is predicated on its retention in the target tissue. Microparticle is one of the most popular and effective drug delivery configurations. Recently, it has been shown that the interaction between drug-loaded microparticles and tissues is related to the effectiveness of paclitaxel delivery to the bladder wall of mice for treating superficial bladder cancer.
In this study, the adhesive interaction between poly methylidene malonate 2. Young's modulus of single PMM 2. For plain PMM 2. The adhesion energy of PMM 2. The loading of paclitaxel in PMM 2. It is hypothesized that the electrostatic repulsion between paclitaxel and collagen at pH 4 reduces the adhesion energy of PMM 2.
This study may offer insight for design of future microparticulate delivery systems by providing the experimental and theoretical tools to study the bioadhesive interaction between drug-loaded microparticles and model extracellular matrices. MR imaging of biodegradable polymeric microparticles: A potential method of monitoring local drug delivery.
Gadolinium diethylenetriamine pentaacetic acid Gd-DTPA was encapsulated into biodegradable, bioadhesive polymeric microparticles to enable noninvasive monitoring of their local intravesical delivery with MRI.
The microparticles were characterized by contrast agent encapsulation and release kinetics, T 1 relaxation rates, and contrast enhancement in vivo.
MR images showed ring-shaped regions of enhancement inscribing the bladder wall, which were attributed to the microparticles that were preferentially adherent to the mucosa lining the urothelium. The images of controls exhibited no such enhancement. Contrast enhancement was observed for at least 5 days after the initial instillation, although the enhancement decreased due to microparticle degradation or mucosa renewal. The localized distribution of biodegradable, bioadhesive microparticles encapsulating Gd-DTPA was successfully visualized with MRI in vivo, allowing particle-mediated delivery to be temporally and spatially monitored noninvasively.
Particle uptake by Peyer's patches: A pathway for drug and vaccine delivery. Particle uptake by Peyer's patches offers the possibility of tailoring vaccines that can be delivered orally. However, particle uptake by the follicle-associated epithelium in the gastrointestinal tract depends on several different factors that are the physicochemical properties of the particles, the physiopathological state of the animal, the analytical method used to evaluate the uptake and finally the experimental model.
These parameters do not allow a clear idea about the optimal conditions to target the Peyer's patches. The goal of this review is to clarify the role of each factor in this uptake. Sustained delivery of growth factors from methylidene malonate 2. The incorporation of growth factors into new methylidene malonate 2.
Five growth factors were used in this study: Formulation in poly methylidene malonate 2. Once dried, formulations could be subsequently stored at 4 or 20 degrees C or immediately subjected to degradation in conditioned cell culture medium.
Toxicity of blends and their degradation products were evaluated in several cell lines with MTT. Bioactivity and biospecificity of the formulated growth factors were investigated using MTT and immunohistochemical staining. Combined ELISA and crystal violet colorimetric assays were performed to analyze growth factors release. Limited toxicities were observed for unloaded poly methylidene malonate 2. Once optimized, growth factors formulations did not reveal lower bioactivities or loss of biospecificity.
To conclude, dual growth factor delivery was made possible by the mean of poly methylidene malonate 2. These studies demonstrate the ability of methylidene malonate 2. Poly methylidene malonate 2. Bioactivity of the released paclitaxel was confirmed by assessing cytotoxicity on MBT-2, a bladder cancer cell line. Biodistribution of particles after bladder instillation was assessed by confocal microscopy and scanning electron microscopy.
The efficacy of intravesical injections of conventional and microsphere paclitaxel was assessed by histology and survival rates.
After bladder instillation the microspheres adhered to the mucosa and remained in the bladder lumen for at least 48 hours.
In the BBN induced bladder cancer model compared with controls the 9-week survival rate was significantly improved by 2 injections of paclitaxel bio-adhesive microparticles. Microscopic evaluation confirmed the lower incidence of carcinoma in situ and high grade transitional cell carcinoma after injections of paclitaxel bio-adhesive microparticles compared with controls and with injections of similar doses of the conventional paclitaxel formulation.
Intravesical administration of poly methylidene malonate 2. The brain tissue response to biodegradable poly methylidene malonate 2. The aim of this study was to follow the in vivo biodegradation as well as to appreciate the brain tissue response to poly methylidene malonate 2.
Ninety-three adult Sprague-Dawley female rats were engaged in the study in which 54 underwent stereotactic implantation of blank gamma-sterilized PMM 2. Twelve rats were implanted with the same 5-fluorouracil 5-FU -loaded microspheres. Seventeen controls received the suspension medium alone carboxymethylcellulose aqueous solution. The animals were sacrificed on post-operative days 1, 2, 8 and months 1, 2, 3, 6, 9, 12, 15 and The brains were dissected, frozen, cut in a freezing microtome, and the slides were processed for immunohistological evaluation and scanning electron microscopy.
During the first few days, the moderate inflammatory response to blank or loaded PMM 2. The macrophagous-microglial reaction was similar to the one typically found following any damage in the CNS. There were also no differences in GFAP reactivity between the implanted animals and the controls.
Blank microspheres began to degrade between 3 and 6 months, while 5-FU microspheres degraded between 8 days and 1 month.
The polymer degradation generated in both cases a pronounced inflammatory and immunological reaction, leading to an important cell loss, a cerebral atrophy and to the death of several animals. Biocompatible poly methylidene malonate -made materials for pharmaceutical and biomedical applications. In the past 20 years, mainly with the sponsorship of Laboratoires UPSA France and, afterwards, its spin-off company Virsol France , several authors have studied methylidene malonate-based polymers used in drug delivery approaches and in the development of novel biomaterials.
The present paper aims at summing up the preparation of methylidene malonate monomers, and essentially a novel asymmetric diester structure: Their polymeric and copolymeric derivatives and a few of their applications which were reported in the literature are also presented. It encompasses the manufacturing of particulate systems such as nano- and macroparticles designed for the delivery of hydrophilic or hydrophobic drugs and biomolecules.
This review article also describes their use as biomaterials of interest in the fields of tissue repair, as drug reservoirs or ophthalmology, as implants. Copolymers based on these monomers offer a large range of properties and could be used as new surfactants, micellar vectors, or particulate systems for gene delivery.
Therefore, this review, certainly the first dedicated exclusively to methylidene malonate-based materials, highlights the great biomedical and pharmaceutical technology potential of these new materials.
A 1-hr in vivo enzyme inhibition assay based on esterase activity has good potential for marine toxicity assessment. A test was developed for the rotifer Brachionus plicatilis based on the nonfluorescent substrate fluorescein diacetate FDA , which is metabolized by esterases to a fluorescent product.
Enzyme inhibition, as determined by reduced fluorescence, can be scored visually or quantified using a fluorometer. The 1-hr esterase inhibition test has sensitivity comparable to that of hr rotifer acute tests for several compounds. The toxicity of six compounds was examined using the quantified assay. The resulting IC20s were within a factor of 3 of the hour LC50s. IC20 values ranged from 0.
Electrophoretic analysis of rotifer homogenates suggested that a single C esterase acetylesterase was responsible for FDA metabolism in B. Several other aquatic species are capable of metabolizing FDA, including Brachionus calyciflorus, Mysidopsis bahia, Menidia beryllina, Pimephales promelas, Ceriodaphnia dubia, Daphnia pulex, Artemia salina, and Ophryotrocha sp. The esterase inhibition test is an attractive tool for assessing aquatic toxicity because of its speed, simplicity, sensitivity, and applicability to a broad range of aquatic species.
Biodegradable poly D,L-lactic acid PLA50 nanoparticles coated with either a readily digestible protein, albumin, or a non-digestible polymer, polyvinyl alcohol, were prepared by the solvent evaporation technique. PLA50 degradation was determined using size exclusion chromatography as well as the enzymatic detection of lactate in bulk solution.
In pepsin-rich simulated gastric fluid, similar behaviour was observed for both nanoparticle systems: In pancreatin-rich simulated intestinal fluid, however, the degradation of the PLA50 matrix was different, depending on the agent coating the nanoparticles: Thus, a direct relationship between degradability of the coating agent and subsequent PLA50 degradation in simulated intestinal fluid was established.
Controlled vaccine release in the gut-associated lymphoid tissues. Orally administered biodegradable microspheres target the Peyer's patches.
Microspheres prepared from various polymers were evaluated for their usefulness as carriers for the targeted delivery of vaccine antigens to the gut-associated lymphoid tissues. Following oral administration to mice, microspheres consisting of polystyrene, poly methyl methacrylate , poly hydroxybutyrate , poly dl-lactide , poly l-lactide , and of poly dl-lactide-co-glycolide with various ratios of lactide to glycolide were absorbed into the Peyer's patches of the small intestine.
In contrast, no or very little uptake was observed with microspheres consisting of ethyl cellulose, cellulose acetate hydrogen phthalate or cellulose triacetate. Poly dl-lactide-co-glycolide microspheres containing a toxoid vaccine of staphylococcal enterotoxin B were prepared and characterized for their size distribution, surface morphology and toxoid release kinetics in an aqueous environment.
Oral immunization with these microspheres effectively delivered and released the vaccine in the gutassociated lymphoid tissue as determined by their ability to induce a disseminated mucosal IgA anti-toxin antibody response.
Nanoparticles as carriers for oral peptide absorption: Studies on particle uptake and fate. Previous work from our laboratories has provided quantitative proof of the importance of the gut associated lymphoid tissue GALT in the processes involved in the uptake of polystyrene nanoparticles delivered orally, and has confirmed the role of the Peyer's patches in the uptake of particles through the small intestine.
In more recent work discussed here the role of lymphoid tissue in the large intestine has been demonstrated, a significant amount of the total uptake occurring in this region of the gut. All children, except those with specific sensory or cognitive disabilities, will learn to speak without apparently having any tuition. In contrast, many people do not become proficient writers and readers.
The two kinds of language use also clearly involve different perceptual skills. There is in addition the matter of the different ages at which speech and literacy normally develop. Until quite recently, as Olson implies, it was also commonly asserted by researchers that the two modes of speech and writing were different in their nature. Speech is usually spontaneous and its sound fades rapidly, while writing is commonly planned and may be drafted; and as a product it may persist for centuries, and can be read and re-read many times.
It was also argued that the two modes are commonly associated with different kinds of communicative function. For these various reasons, it was concluded that the different modes necessarily require the use of rather different compositional and comprehension skills.
Again, there is certainly some truth in these claims. But in recent times the general validity of this bi-modal view of speech and writing as very distinct language modes has been questioned.
Olson briefly mentions some reasons why this is so, and others can be found. Speech can also be recorded, so it need not fade rapidly, and can be replayed for multiple hearings. Moreover, with the advent of information technology new ways of using language are emerging which make it difficult to continue to argue that the two modes are completely distinct in nature, or in the skills they require for their use.
Consider, for example, the use of email, conferencing and other similar kinds of computer-based communication. We will be looking at those kinds of language use, and at multimodal communication, in section 4. For further information, take a look at our frequently asked questions which may give you the support you need.
Oral Biopsy in General Dental Practice: A Review
In vitro and in vivo Evaluation of Poly(Methylidene Malonate ) Microparticles Behavior for Oral Administration. Denture status 55 Intervention urgency Section 2: Oral health self- assessment Self-assessment of oral health and risks Oral. Significant oral injury will still occur in spite of preventive activities. Sports during which protective equipment for the head is worn, which may thus.