Diclofenac sustained release from sterilised soft contact lens materials using an optimised layer-by-layer coating.

A layer-by-layer (LbL) coating was designed using ionic polysaccharides (chitosan, sodium alginate, sodium hyaluronate) and genipin (crosslinker), to sustain the release of diclofenac sodium salt (DCF) from soft contact lens (SCL) materials. The coating was hydrophilic, biocompatible, non-toxic, reduced bacterial growth and had minor effects on the physical properties of the material, such as wettability, ionic permeability, refractive index and transmittance, which remained within the recommended values for SCLs. The coating was applied on a silicone-based hydrogel and on commercial SofLens and Purevision SCLs. The coating attenuated the initial drug burst and extended the therapeutic period for, at least, two weeks. Relevantly, the problems of sterilizing drug loaded SCLs coated with biopolymers, using classic methods that involve high temperature or radiation, were successfully solved through high hydrostatic pressure (HHP) sterilization.

Optic Nerve Compression From MIRAgel Implant Migration in a Monocular Patient.

The MIRAgel implantation was popularized in the 1980s as an alternative to silicone for scleral buckle retinal detachment repair. However, long-term follow-up has revealed that the implants can expand, creating globe compression and potentially visually devastating intraocular invasion. The authors document a 33-year-old monocular male patient presenting 20 years after MIRAgel implantation with extensive expansion, posterior migration, globe compression, and possible optic nerve compression. Debulking of the MIRAgel stabilized the vision and restored affected extraocular movements. The authors highlight that posterior MIRAgel migration can cause optic nerve compression, and implant debulking may require a multi-disciplinary approach. [Ophthalmic Surg Lasers Imaging Retina. 2018;49:815-818.].

Complications Assoicated with MIRAgel for Treatment of Retinal Detachment.

MIRAgel (MIRA, Waltham, MA) is a hydrogel buckle that was introduced in 1979 as a new scleral implant for the treatment of retinal detachment. Long-term follow-up of more than 10 years revealed that the hydrolysis of the synthetic hydrophilic material leads to marked expansion of the substance, causing complications such as buckle extrusion and intrusion, eye motility disorder, cosmetic deformities, and periocular infections. Removal of the implant is the treatment of choice in cases with complications, but it is technically difficult due to the friability of the implant, severe scleral ectasia, and relatively high rate of redetachment after removal.

MIRAgel Buckle Extrusion With Preseptal Cellulitis and Erosion Through the Eyelid Skin.

MIRAgel (MIRA, Waltham, MA) scleral buckle material was initially developed in the 1980s as an alternative to more traditional silicone buckles. Long-term follow-up has demonstrated complications necessitating removal due to unanticipated hydrolytic degeneration of the exoplant. Material expansion and fragmentation have led to pain, limited extraocular motility, ocular masses, infection, and eventual extrusion. Complications occur later than in other materials; most patients need removal an average of 7 years to 13 years after implantation. This case describes a previously not reported case of MIRAgel scleral buckle extrusion complicated by preseptal cellulitis and complete erosion of the material through the inferior eyelid and extrusion through the skin. [Ophthalmic Surg Lasers Imaging Retina. 2016;47:1147-1150.].

Evaluation of Bone Regeneration on Polyhydroxyethyl-polymethyl Methacrylate Membrane in a Rabbit Calvarial Defect Model.

This study was conducted to evaluate the capacity of guiding bone regeneration of polyhydroxyethyl-polymethyl methacrylate (PHEMA-PMMA) membrane as a guided tissue regeneration membrane for bone defects. Two 8-mm diameter transosseous round defects were made at the parietal bone of 18 New Zealand White rabbits. Defects were covered with or without PHEMA-PMMA membrane. Radiological and histological evaluation revealed that the bone tissue over the defect was more regenerated with time in both groups. However, there was significantly more bone regeneration at 8 weeks in the experimental group than the control group (p<0.05). There was no sign of membrane degradation or tissue inflammation and no invasion of muscle and fibrous tissue into defects. PHEMA-PMMA is a potential material for guided tissue regeneration membrane as it induces no adverse tissue reaction and effectively supports selective bone regeneration.

The Removal of Hydrogel Explants: An Analysis of 467 Consecutive Cases.

PURPOSE: To describe the complications associated with hydrogel explants and to describe the indications, surgical technique, and risks involved in the removal of a hydrogel explant. DESIGN: Single-center, retrospective interventional case series. PARTICIPANTS: Patients who underwent surgical removal of a symptomatic, swollen hydrogel explant. METHODS: We reviewed the medical records of 457 consecutive patients (467 eyes in total) who underwent surgical removal of a symptomatic, swollen episcleral MIRAgel (MIRA Inc., Waltham, MA) explant at the Radboud University Medical Center from 1998 to 2011. We reviewed the initial symptoms, clinical findings, surgical aspects, and intraoperative and postoperative complications. MAIN OUTCOME MEASURES: Presenting symptoms, retinal redetachment rate, and intraoperative scleral perforation. RESULTS: The median interval between initial placement of the hydrogel explant and removal of the explant was 159 months. More than 34% of the episcleral hydrogel explants developed symptomatic swelling and required surgical removal. Intraoperative scleral perforation or retinal redetachment related to the removal of the explant occurred in 11% of patients. CONCLUSIONS: The percentage of explants that ultimately develop symptomatic swelling is considerably higher than reported previously. A swollen hydrogel explant can be removed many years after the primary detachment surgery, and 11% of cases develop intraoperative scleral perforation or retinal redetachment.

Globe Loss From Intraocular Invasion of MIRAgel Scleral Buckle Components.

PURPOSE: To describe intraocular invasion of MIRAgel scleral buckles requiring evisceration. METHODS: This is an Institutional Review Board-approved retrospective consecutive case series of eyes requiring evisceration secondary to intraocular intrusion of MIRAgel implants performed at the Cole Eye Institute from 2000 to 2014. Charts were reviewed for age at surgery, gender, laterality, time between MIRAgel placement and evisceration, preoperative examination and imaging results, intraoperative findings, postoperative complications, and duration of follow up. RESULTS: Five eyes of 5 patients underwent evisceration due to a blind, painful eye secondary to MIRAgel expansion. The mean time between MIRAgel placement and evisceration was 21 years (range: 17-30 years). Preoperative ultrasound identified intraocular MIRAgel in 3 of 5 cases; however, intraocular MIRAgel was identified during surgery in all 5 cases. A transocular-approach orbitotomy was performed at the time of evisceration in an effort to remove the MIRAgel. Postoperative complications included ptosis and inability to retain an ocular prosthesis. No cases of orbital implant extrusion occurred. CONCLUSION: Scleral invasion and intraocular penetration of MIRAgel may occur decades after placement. This may result in a blind, painful eye requiring evisceration and orbitotomy to remove residual material. Suspicion of intraocular penetration of implant should be high in blind, painful eyes. Surgical removal can be difficult due to MIRAgel fragmentation. Conjunctival insufficiency may result in the need for further surgery after evisceration.

Granulomatous foreign-body reactions to permanent fillers: detection of CD123+ plasmacytoid dendritic cells.

BACKGROUND: Soft-tissue augmentation with permanent fillers can lead to severe granulomatous foreign-body reactions (GFBRs), but the immune pathomechanism of this complication is still unknown. We performed conventional histologic examination and immunostaining for plasmacytoid dendritic cells (pDCs) in skin sections from patients with GFBR to 4 permanent filler agents, which have been widely used in recent decades. METHODS: Twenty-one skin biopsies were studied from 19 patients with GFBR to polyalkylimide 4% gel (PAIG, n = 10), polyacrylamide 2.5% gel (PAAG, n = 2), hydroxyethyl methacrylate/ethyl methacrylate in hyaluronic acid (HEMA/EMA, n = 4), or liquid injectable silicone (n = 5). GFBRs were analyzed in hematoxylin and eosin stained sections and pDCs detected using CD123 antibodies. Anti-CD11c immunostaining was performed for comparison. RESULTS: Grading of the inflammatory infiltrates observed histologically did not correlate with the clinical features of inflammation. Immunostaining for CD123 did not detect pDCs in 8 of 10 polyalkylimide gel, 1 of 2 polyacrylamide gel, and the 5 liquid injectable silicone biopsies. In contrast, all 4 HEMA/EMA biopsies contained collections of pDCs in lymphocytic infiltrates close to filler particles and adjacent sarcoidal granulomas. CONCLUSIONS: Our data suggest that pDCs contribute to the sarcoidal granulomas associated with injected HEMA/EMA. Recruited pDCs may exert their pro-inflammatory effects by the release of interferon-α at the site of these filler deposits.

Coculture with intraocular lens material-activated macrophages induces an inflammatory phenotype in lens epithelial cells.

Cataracts are the leading cause of blindness worldwide, requiring surgical implantation of an intraocular lens. Despite evidence of leukocyte ingress into the postoperative lens, few studies have investigated the leukocyte response to intraocular lens materials. A novel coculture model was developed to examine macrophage activation by hydrophilic acrylic (poly(2-hydroxyethyl methacrylate)) and hydrophobic acrylic (polymethylmethacrylate) commercial intraocular lens. The human monocytic cell line THP-1 was differentiated into macrophages and cocultured with human lens epithelial cell line (HLE-B3) with or without an intraocular lens for one, two, four, or six days. Using flow cytometry and confocal microscopy, expression of the macrophage activation marker CD54 (intercellular adhesion molecule-1) and production of reactive oxygen species via the fluorogenic probe 2',7'-dichlorodihydrofluorescein diacetate were examined in macrophages. α-Smooth muscle actin, a transdifferentiation marker, was characterized in lens epithelial cells. The poly(2-hydroxyethyl methacrylate) intraocular lens prevented adhesion but induced significant macrophage activation (p < 0.03) versus control (no intraocular lens), while the polymethylmethacrylate intraocular lens enabled adhesion and multinucleated fusion, but induced no significant activation. Coculture with either intraocular lens increased reactive oxygen species production in macrophages after one day (p < 0.03) and increased expression of α-smooth muscle actin in HLE B-3 after six days, although only poly(2-hydroxyethyl methacrylate) induced a significant difference versus control (p < 0.01). Our results imply that-contrary to prior uveal biocompatibility understanding-macrophage adherence is not necessary for a strong inflammatory response to an intraocular lens, with hydrophilic surfaces inducing higher activation than hydrophobic surfaces. These findings provide a new method of inquiry into uveal biocompatibility, specifically through the quantification of cell-surface markers of leukocyte activation.

Bovine serum albumin-meloxicam nanoaggregates laden contact lenses for ophthalmic drug delivery in treatment of postcataract endophthalmitis.

Postcataract endophthalmitis treatment through eye drops is of low corneal bioavailability and short residence time. The dominant NSAIDs therapy also suffers from severe ocular irritancy and low patients compliance. This study dispersed bovine serum albumin (BSA) coated meloxicam (MX) nanocrystals encapsulating nanoaggregates (BSA-MX-NA) in contact lenses to reduce drug ocular irritancy and increased drug release duration. The BSA-MX-NA (∼100 nm) were prepared using acid-base neutralization in aqueous solutions and were dispersed in poly(hydroxylethyl methacrylate) gels, which are common contact lens materials. Drug release studies showed that the gels released the drug for about 5 days. The proposed drug transport mechanism is a diffusion process which can be described by the Ritger-Peppas model with the diffusional exponent n of 0.4768. The drug release can be affected by the gel thickness and the cross-linking degree. A 400 micro thick gels with 100 µL cross-linker TEGDMA leads to an adequate meloxicam release for therapeutic application. The ocular irritation studies showed that BSA-MX-NA loaded p-HEMA gels are significantly less irritating to the ocular tissues as compared to marketed MX solutions. The developed contact lenses loaded with BSA-MX-NA could be very useful for extended delivery in postcataract endophthalmitis treatment.

Inflammatory nodules following soft tissue filler use: a review of causative agents, pathology and treatment options.

Nodule development is a common complication following the use of fillers for soft tissue augmentation and is commonly categorized as inflammatory or non-inflammatory in nature. Inflammatory nodules may appear anywhere from days to years after treatment, whereas non-inflammatory nodules are typically seen immediately following implantation and are usually secondary to improper placement of the filler. Although inflammatory nodules are more common with permanent fillers such as silicone, inflammatory nodule development following administration of temporary fillers such as hyaluronic acid and collagen has also been reported. Treated many times with corticosteroids due to their anti-inflammatory properties, inflammatory nodules may be secondary to infection or biofilm formation, warranting the use of alternative agents. Appropriate and prompt diagnosis is important in avoiding delay of treatment or long-term complications for the patient. This paper addresses the etiology, development, and studied treatment options available for inflammatory nodules secondary to each of the major classes of fillers. With this knowledge, practitioners may expeditiously recognize and manage this common side effect and thus maximize functional and aesthetic benefit.

Hydrogel explant extrusion masquerading as a malignant eyelid lesion.

Hydrogel was a commonly used material for scleral buckling in the early 1980s to the mid-1990s. Use of hydrogel ceased due to a high complication rate, including frequent migration. Various symptoms and clinical findings have been reported with hydrogel migration. There have been no published reports of hydrogel migration to the eyelid anterior to the orbital septum with erosion of the orbicularis and bleeding as a presenting symptom. The authors describe a patient with hydrogel migration to the upper eyelid, with symptomology and clinical findings consistent with a malignant eyelid lesion. Excisional biopsy of extraorbital hydrogel is recommended in these cases.

[A man with progressive diplopia]. / Een man met progressieve diplopie.

A 71-year-old man presented with progressive diplopia due to swelling of a Miragel explant. Removal of the explant resulted in relief of symptoms.

Outcomes and complications of hydrogel scleral explant removal.

BACKGROUND AND OBJECTIVE: To report symptoms of extrusion of hydrogel explants after retinal detachment (RD) repair and the outcomes and complications following removal. PATIENTS AND METHODS: All 23 patients had previous RD repair by episcleral buckle with hydrogel explant. Signs and symptoms of scleral buckle (SB) extrusion were analyzed. Main outcomes measured were redetachment of the retina, persistent diplopia, and decreased postoperative visual acuity (VA). RESULTS: Mean time between RD repair and removal of extruded SB was 16.2 years (range: 11 to 21 years). Fifteen patients (65%) received encircling SB and 8 had segmental SB. SB was combined with vitrectomy in 12 patients and 3 received silicone oil. Common complaints included limited ocular motility, presence of a palpable mass under the eyelid, pain and discomfort, diplopia, visible SB under eroded conjunctiva, complete immobility, and signs of infection. Two eyes were phthisical. No scleral perforations occurred during removal of explants. After SB removal, RD recurred in 2 patients and diplopia persisted in 4. VA was not affected by SB removal. CONCLUSION: Deterioration may occur after implantation for 10 years or longer. This is due to microstructural change of the hydrogel material. The most common problems are motility disturbance and presence of a tumor-like, palpable mass under the eyelid. Removal of the implant can alleviate some ocular problems. However, RD can recur and diplopia may persist after removal of the SB. Vision usually is not affected.

Cutaneous and inflammatory response to long-term percutaneous implants of sphere-templated porous/solid poly(HEMA) and silicone in mice.

This study investigates mouse cutaneous responses to long-term percutaneously implanted rods surrounded by sphere-templated porous biomaterials engineered to mimic medical devices surrounded by a porous cuff. We hypothesized that keratinocytes would migrate through the pores and stop, permigrate, or marsupialize along the porous/solid interface. Porous/solid-core poly(2-hydroxyethyl methacrylate) [poly(HEMA)] and silicone rods were implanted in mice for 14 days, and for 1, 3, and 6 months. Implants with surrounding tissue were analyzed (immuno)histochemically by light microscopy. Poly(HEMA)/skin implants yielded better morphologic data than silicone implants. Keratinocytes at the poly(HEMA) interface migrated in two different directions. "Ventral" keratinocytes contiguous with the dermal-epidermal junction migrated into the outermost pores, forming an integrated collar surrounding the rods. "Dorsal" keratinocytes appearing to emanate from the differentiated epithelial layer, extended upward along and into the exterior portion of the rod, forming an integrated sheath. Leukocytes persisted in poly(HEMA) and silicone pores for the duration of the study. Vascular and collagen networks within the poly(HEMA) pores matured as a function of time up to 3-months implantation. Nerves were not observed within the pores. Poly(HEMA) underwent morphological changes by 6 months of implantation. Marsupialization, foreign body encapsulation, and infection were not observed in any implants.

Adverse reactions caused by consecutive injections of different fillers in the same facial region: risk assessment based on the results from the Injectable Filler Safety study.

BACKGROUND: The combination of different injectable fillers in one area is considered to increase the risk of adverse reactions. OBJECTIVES: To characterize adverse reactions in patients who received more than one filler in the same facial region. METHODS: Data (up to July 2009) of the Injectable Filler Safety Study, a German-based registry for adverse filler reactions, was analysed descriptively. All cases were discussed individually. RESULTS: In 22 of the 161 patients (13.7%), two or more different fillers were injected consecutively into the same facial region. All patients were female with an average age of 50.6 (SD 13.6) years. In 12 of the 22 patients (54.5%), a specific filler could be attributed to the adverse reactions whereas in the other 10 patients (45.5%), the filler was not clearly attributable to one filler substance causing the adverse reactions. CONCLUSIONS: With the continuous changes in the filler market, the combination of different fillers in one area becomes more likely. Based on our data, there is not a lot of evidence that the combination of different injectable fillers, specifically biodegradable fillers, in the same region increases the risk of adverse reactions.

Evaluation of peritoneal adhesions formation and tissue response to polypropylene - poli (2-hydroxyethyl methacrylate)-(polyHEMA) implant on rats' abdominal wall.

PURPOSE: To verify if the composit poli (2-hydroxyethyl methacrylate)-PolyHEMA/polypropylene mesh implanted in the female rat's abdominal wall could be suitable for the prevention of peritoneal adhesions, and for the evaluation of the tecidual response produced by this biomaterial. METHODS: Polypropylene meshes (Group PP, n=20) and polypropylene meshes coated with a layer of poli (2-hydroxyethyl methacrylate)-PolyHEMA (Group PH, n=20) were implanted on the abdominal wall of Wistar female rats. Ten animals from each group were submitted to euthanasia at 15 and 30 days of the postoperative period. RESULTS: The animals from the group PP presented visceral adhesions on the mesh surface, which was not observed in the ones from group PH. At the histopathological examination foreign body response was observed in both groups, whilst there was a greater intensity of inflammatory response in group PH on both moments. CONCLUSION: The poli (2-hydroxyethyl methacrylate) polyHEMA hydrogel associated to polypropylene mesh reduces visceral adhesion formation in rats, although it may be associated to greater inflammatory reaction.

Clarification of the blood compatibility mechanism by controlling the water structure at the blood-poly(meth)acrylate interface.

In previous studies, we reported that poly(2-methoxyethyl acrylate) (PMEA) exhibited excellent blood compatibility, although it has a simple chemical structure. Since then, we have been investigating the reasons for its blood compatibility. In this short review, we consider the reasons for this compatibility by comparing the structure of water in hydrated PMEA to the water structure of poly(2-hydroxyethyl methacrylate) (PHEMA) and poly(meth)acrylate analogs as reference polymers. The hydrated water in PMEA could be classified into three types; free water (or freezing water), freezing-bound water (or intermediate water), and non-freezing water (or non-freezing-bound water). We found that hydrated PMEA possessed a unique water structure, observed as cold crystallization of water in differential scanning calorimetry (DSC). Cold crystallization is interpreted as ice formation at low temperature, an attribute of freezing-bound water in PMEA. The cold crystallization peak was observed for hydrated poly(ethylene glycol) (PEG), poly(vinyl methyl ether) (PVME), polyvinylpyrrolidone (PVP), poly(2-methacryloyloxyethyl phosphorylcholine) (PMPC), poly(tetrahydrofurfuryl acrylate) (PTHFA), and newly synthesized poly(2-(2-ethoxyethoxy)ethyl acrylate), as well as various proteins and polysaccharides, which are well-known biocompatible polymers. On the other hand, cold crystallization of water was not observed in hydrated PHEMA and PMEA analogous polymers, which do not show excellent blood compatibility. Based on these findings, we hypothesized that freezing-bound water, which prevents the biocomponents from directly contacting the polymer surface or non-freezing water on the polymer surface, plays an important role in the excellent blood compatibility of PMEA.

Evaluation of peritoneal adhesions formation and tissue response to polypropylene - poli (2-hydroxyethyl methacrylate)-(polyHEMA) implant on rats' abdominal wall / Avaliação da formação de aderências peritoneais e da resposta tecidual ao implante de poli (2-hidroxietil dimetacrilato)-(poliHEMA) na parede abdominal de ratos

PURPOSE: To verify if the composit poli (2-hydroxyethyl methacrylate)-PolyHEMA/polypropylene mesh implanted in the female rat's abdominal wall could be suitable for the prevention of peritoneal adhesions, and for the evaluation of the tecidual response produced by this biomaterial. METHODS: Polypropylene meshes (Group PP, n=20) and polypropylene meshes coated with a layer of poli (2-hydroxyethyl methacrylate)-PolyHEMA (Group PH, n=20) were implanted on the abdominal wall of Wistar female rats. Ten animals from each group were submitted to euthanasia at 15 and 30 days of the postoperative period. RESULTS: The animals from the group PP presented visceral adhesions on the mesh surface, which was not observed in the ones from group PH. At the histopathological examination foreign body response was observed in both groups, whilst there was a greater intensity of inflammatory response in group PH on both moments. CONCLUSION: The poli (2-hydroxyethyl methacrylate) polyHEMA hydrogel associated to polypropylene mesh reduces visceral adhesion formation in rats, although it may be associated to greater inflammatory reaction.

OBJETIVO: Verificar se compósito poli 2-hidroxietil dimetacrilato (PoliHEMA) / tela de polipropileno implantado na parede abdominal de ratas seria adequado para prevenção de aderências peritoneais e avaliar a resposta tecidual desencadeada por este biomaterial. MÉTODOS: Foram implantadas telas de polipropileno - Grupo PP (n=20) e telas de polipropileno revestidas por uma camada de poli 2 (hidroxietil dimetacrilato)-PolyHEMA - Grupo PH (n=20) na parede abdominal de ratas da linhagem Wistar. Dez animais de cada grupo foram submetidos à eutanásia aos 15 e 30 dias de pós-operatório. RESULTADOS: Os animais do grupo PP apresentaram aderências viscerais na superfície da tela, o que não foi observado nos do grupo PH. Observou-se no exame histopatológico resposta tipo corpo estranho nos dois grupos sendo que no grupo PH houve maior intensidade de resposta inflamatória nos dois momentos. CONCLUSÃO: O hidrogel de poliHEMA quando associado à tela de polipropileno reduz a formação de aderências viscerais em ratos, embora possa estar associado à reação inflamatória mais intensa.