A thermoresponsive hydrogel system for long-acting corticosteroid delivery into the paranasal sinuses.
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ABSTRACT:
SUBMITTER: Schilling AL
PROVIDER: S-EPMC8444195 | biostudies-literature |
REPOSITORIES: biostudies-literature
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| S-EPMC8257169 | biostudies-literature
Project description:BackgroundThe paranasal sinuses are complex anatomical structures, characterised by highly variable shape, morphology and size. With the introduction of multidetector scanners and the development of many post-processing possibilities, computed tomography became the gold standard technique to image the paranasal sinuses. Segmentation allows the extraction of metrical and shape data of these anatomical components that can be applied for diagnostic, education, surgical planning and simulation, and to plan minimally invasive interventions in otorhinolaryngology and neurosurgery.DiscussionOur aim was to provide a review of the existing literature on segmentation, its types and application, and the data obtained from this procedure. The literature search was conducted on PubMed (including Medline), ScienceDirect and Google Scholar databases, using the keywords as follows: 'paranasal sinuses', 'frontal sinus', 'maxillary sinus', 'sphenoid sinus', 'ethmoid sinus', in all possible combinations with the keywords 'segmentation' and 'volumetric analysis'. Inclusion criteria were: articles written in English, on living human subjects, on the adult population and focused on paranasal sinuses analysis.ConclusionThis article provides an overview of the types and main application of segmentation procedures on paranasal sinuses, and the results provided by the studies on this topic.
| S-EPMC7868593 | biostudies-literature
Project description:Rhinosinusitis (RS) is an acute (ARS) or chronic (CRS) inflammatory disease of the nasal and paranasal sinus mucosa. CRS is a heterogeneous condition characterized by distinct inflammatory patterns (endotypes) and phenotypes associated with the presence (CRSwNP) or absence (CRSsNP) of nasal polyps. Mucosal barrier and mucociliary clearance dysfunction, inflammatory cell infiltration, mucus hypersecretion, and tissue remodeling are the hallmarks of CRS. However, the underlying factors, their priority, and the mechanisms of inflammatory responses remain unclear. Several hypotheses have been proposed that link CRS etiology and pathogenesis with host (eg, "immune barrier") and exogenous factors (eg, bacterial/fungal pathogens, dysbiotic microbiota/biofilms, or staphylococcal superantigens). The abnormal interplay between these factors is likely central to the pathophysiology of CRS by triggering compensatory immune responses. Here, we discuss the role of the sinonasal microbiota in CRS and its biofilms in the context of mucosal zinc (Zn) deficiency, serving as a possible unifying link between five host and "bacterial" hypotheses of CRS that lead to sinus mucosa remodeling. To date, no clear correlation between sinonasal microbiota and CRS has been established. However, the predominance of Corynebacteria and Staphylococci and their interspecies relationships likely play a vital role in the formation of the CRS-associated microbiota. Zn-mediated "nutritional immunity", exerted via calprotectin, alongside the dysregulation of Zn-dependent cellular processes, could be a crucial microbiota-shaping factor in CRS. Similar to cystic fibrosis (CF), the role of SPLUNC1-mediated regulation of mucus volume and pH in CRS has been considered. We complement the biofilms' "mechanistic" and "mucin" hypotheses behind CRS pathogenesis with the "structural" one - associated with bacterial "corncob" structures. Finally, microbiota restoration approaches for CRS prevention and treatment are reviewed, including pre- and probiotics, as well as Nasal Microbiota Transplantation (NMT).
| S-EPMC10906676 | biostudies-literature
Project description:Diseases of the pediatric nose and nasal sinuses as well as neighboring anatomical structures encompass a variety of pathologies, especially of inflammatory nature. Congenital disease, such as malformations and structural deviations of the nasal septum, as well as systemic metabolic pathologies affecting the nose and sinuses, rarely require medical therapy from an Otolaryngologist. The immunological function of the mucosa and genetic factors play a role in the development of disease in the pediatric upper airway tract, especially due to the constantly changing anatomy in this growth phase. Disease description of the nose and nasal sinuses due to mid-facial growth must also take developmental age differences (infant, toddler, preschool, and school age) into account. Epidemiological examinations and evidence based studies are often lacking in the pediatric population. The wide range of inflammatory diseases of the nose and paranasal sinuses, such as the acute and chronic rhinosinusitis, the allergic rhinitis, and adenoid disease, play a role in the susceptibility of a child to infection. The susceptibility to infection depends on the pediatric age structure (infant, young child) and has yet to be well defined. The acute rhinosinusitis in children develops after a viral infection of the upper airways, also referred to as the "common cold" in the literature. It usually spontaneously heals within ten days without any medical therapy. Antibiotic therapy is prudent in complicated episodes of ARS. The antibiotic therapy is reserved for children with complications or associated disease, such as bronchial asthma and/or chronic bronchitis. A chronic rhinosinusitis is defined as the inflammatory change in the nasal mucosa and nasal sinus mucosa, in which the corresponding symptoms persist for over 12 weeks. The indication for CT-imaging of the nasal sinuses is reserved for cases of chronic rhinosinusitis that have been successfully treated with medication. A staged therapeutic concept is followed in CRS based on conservative and surgical methods. Nasal sinus surgery is considered nowadays as effective and safe in children. Based on the assumption that adenoids are a reservoir for bacteria, from which recurrent infections of the nose and nasal sinus originate, the adenoidectomy is still defined as a cleansing procedure in rhinosinusitis. 69.3% of the children had benefit from adenoidectomy. Comorbidities, such as pediatric bronchial asthma, presently play an even more important role in the therapy of rhinosinusitis; therefore, it is often wise to have the support of pediatricians. In western European countries 40% of children presently suffer from allergic rhinitis, in which pronounced nasal obstruction can cause disturbed growth in facial bones. An early therapy with SIT may prevent the development of bronchial asthma and secondary sensitization to other allergens. Therefore, SIT is recommended in treatment of allergic rhinitis whenever, if possible. The assessment of diagnostic tools is for the examiner not often possible due to the lack of evidence. Rhinosurgical approaches are often described in study reports; however, they lack the standard prospective randomized long-term study design required nowadays and can only be evaluated with caution in the literature.
| S-EPMC4273171 | biostudies-other
Project description:Responsive polymeric hydrogels have found wide application in the clinic as injectable, biocompatible, and biodegradable materials capable of controlled release of therapeutics. In this article, we introduce a thermoresponsive polymer hydrogel bearing covalent disulfide bonds. The cold aqueous polymer solution forms a hydrogel upon heating to physiological temperatures and undergoes slow degradation by hydrolytic cleavage of ester bonds. The disulfide functionality allows for immediate reductive cleavage of the redox-sensitive bond embedded within the polymer structure, affording the option of instantaneous hydrogel collapse. Poly(ethylene glycol)-b-poly(lactic acid)-S-S-poly(lactic acid)-b-poly(ethylene glycol) (PEG-PLA-SS-PLA-PEG) copolymer was synthesized by grafting PEG to PLA-SS-PLA via urethane linkages. The aqueous solution of the resultant copolymer was a free-flowing solution at ambient temperatures and formed a hydrogel above 32 °C. The immediate collapsibility of the hydrogel was displayed via reaction with NaBH4 as a relatively strong reducing agent, yet stability was displayed even in glutathione solution, in which the polymer degraded slowly by hydrolytic degradation. The polymeric hydrogel is capable of either long-term or immediate degradation and thus represents an attractive candidate as a biocompatible material for the controlled release of drugs.
| S-EPMC8544516 | biostudies-literature
Project description:The Port Delivery System with ranibizumab (PDS) is an innovative intraocular drug delivery system designed for the continuous delivery of ranibizumab into the vitreous for 6 months and beyond. The PDS includes an ocular implant, a customized formulation of ranibizumab, and four dedicated ancillary devices for initial fill, surgical implantation, refill-exchange, and explantation, if clinically indicated. Ranibizumab is an ideal candidate for the PDS on account of its unique physicochemical stability and high solubility. Controlled release is achieved via passive diffusion through the porous release control element, which is tuned to specific drug characteristics to accomplish a therapeutic level of ranibizumab in the vitreous. To characterize drug release from the implant, release rate was measured in vitro with starting concentrations of ranibizumab 10, 40, and 100 mg/mL, with release of ranibizumab 40 and 100 mg/mL found to remain quantifiable after 6 months. Using a starting concentration of 100 mg/mL, active release rate at approximately 6 months was consistent after the initial fill and first, second, and third refills, demonstrating reproducibility between implants and between multiple refill-exchanges of the same implant. A refill-exchange performed with a single 100-µL stroke using the refill needle was shown to replace over 95% of the implant contents with fresh drug. In vitro data support the use of the PDS with fixed refill-exchange intervals of at least 6 months in clinical trials.
| S-EPMC9067954 | biostudies-literature
Project description:PurposeThe short half lives of small molecules in the vitreous requires frequent repeated intravitreal injections that are impractical for treatment of chronic eye diseases. We sought to develop a method for increasing the intravitreal half-life of small-molecule drugs.MethodsWe adapted a technology for controlled release of drugs from macromolecular carriers for use as a long-acting intravitreal delivery system for small molecules. As a prototype, a small molecule complement factor D inhibitor with an intravitreal half-life of 7 hours was covalently attached to a 4-arm PEG40kDa by a self-cleaving β-eliminative linker with a cleavage half-life of approximately 1 week.ResultsAfter intravitreal injection in rabbits, the drug was slowly released in the vitreous, and equilibrated with the retina and choroid. The intravitreal half-life of the intact PEG-drug conjugate in the rabbit was 7 days, and that of the released drug was 3.6 days. We simulated the anticipated pharmacokinetics of the delivery system in human vitreous, and estimated that the half-life of a 4-arm PEG40kDa conjugate would be approximately 2 weeks, and that of the released drug would be approximately 5 days.ConclusionsWe posit that a linker with a cleavage half life of 2 weeks would confer a half life of approximately 7 days to a released small molecule drug in humans, comparable to the half life of approved intravitreal injected macromolecular drugs.Translational relevanceWith this technology, a potent small molecule with an appropriate therapeutic window should be administrable by intravitreal injections in the human at once-monthly intervals.
| S-EPMC6114027 | biostudies-literature
Project description:Non-adherence to medication is an important health care problem, especially in the treatment of chronic conditions. Injectable long-acting (LA) formulations of antiretrovirals (ARVs) represent a viable alternative to improve adherence to HIV/AIDS treatment and prevention. However, the LA-ARV formulations currently in clinical trials cannot be removed after administration even if adverse events occur. Here we show an ultra-LA removable system that delivers drug for up to 9 months and can be safely removed to stop drug delivery. We use two pre-clinical models for HIV transmission and treatment, non-human primates (NHP) and humanized BLT (bone marrow/liver/thymus) mice and show a single dose of subcutaneously administered ultra-LA dolutegravir effectively delivers the drug in both models and show suppression of viremia and protection from multiple high-dose vaginal HIV challenges in BLT mice. This approach represents a potentially effective strategy for the ultra-LA drug delivery with multiple possible therapeutic applications.
| S-EPMC6175887 | biostudies-other
Project description:Low water solubility frequently compromises the therapeutic efficacy of drugs and other biologically active molecules. Here, we report on coacervate polysaccharide nanoparticles (CPNs) that can transport and release a model hydrophobic drug, piroxicam, to the cells in response to changes in temperature. The proposed, temperature-responsive drug delivery system is based on ionic derivatives of natural polysaccharides-curdlan and hydroxypropyl cellulose. Curdlan was modified with trimethylammonium groups, while the anionic derivative of hydroxypropyl cellulose was obtained by the introduction of styrenesulfonate groups. Thermally responsive nanoparticles of spherical shape and average hydrodynamic diameter in the range of 250-300 nm were spontaneously formed in water from the obtained ionic polysaccharides as a result of the coacervation process. Their morphology was visualized using SEM and AFM. The size and the surface charge of the obtained objects could be tailored by adjusting the polycation/polyanion ratio. Piroxicam (PIX) was effectively entrapped inside the nanoparticles. The release profile of the drug from the CPNs-PIX was found to be temperature-dependent in the range relevant for biomedical applications.
| S-EPMC7767055 | biostudies-literature
Project description:Objectives To identify sinuses demonstrating postoperative radiographic mucosal thickening after endoscopic exposure of the cranial base through the transsphenoidal corridor. Design Retrospective review. Setting University-based medical center. Participants Patients undergoing endoscopic transnasal transsphenoidal approaches to the skull base who had both preoperative and postoperative imaging. Main Outcome Measures Change in preoperative and postoperative imaging scores for each sinus and side at 3 and 6 months. The left-sided undissected sinuses served as internal controls for comparison. Results Fifty-one patients were identified with the aforementioned inclusion and exclusion criteria. The mean difference in preoperative and postoperative imaging scores for the right anterior ethmoid sinus was significantly different from the left-sided equivalents (p = 0.0020). The difference in the frontal sinuses approached significance (p = 0.0625). Conclusions Resection of the lower half of the middle turbinate and maxillary antrostomy and harvest of a nasoseptal flap are associated with an increased radiographic incidence of mucosal thickening of the ipsilateral anterior ethmoids compared with the undissected contralateral side. When accessing the transnasal transsphenoidal corridor for skull base surgery, preservation of native anatomy is associated with a lower incidence of mucosal thickening on postoperative imaging.
| S-EPMC3836810 | biostudies-other