Temperature-sensitive hydrogels composed of chitosan and hyaluronic acid as injectable carriers for drug delivery.

Temperature-sensitive hydrogels composed of poly(N-isopropylacrylamide) (PNIPAAm) with chitosan (CPN) and chitosan+hyaluronic acid (CPNHA) were grafted in order to examine their physicochemical characteristics, in vitro drug release, and in vivo pharmacodynamics. The sol-gel transition behavior was investigated by UV/visible spectrophotometry, differential scanning calorimetry, and viscometry. A slight difference in the transition temperatures was observed among these polymer systems, with CPN and CPNHA exhibiting higher temperatures compared with PNIPAAm. A zeta potential determination revealed a positive charge for the CPN hydrogel, whereas no or only a negligible charge was observed for PNIPAAm and CPNHA. The entanglement of CPN hydrogels observed using scanning electronic microscopy showed the densest cross-linkage structure, followed by CPNHA and PNIPAAm. Both hydrophilic and lipophilic drugs, including nalbuphine, indomethacin, and the nalbuphine prodrug, were used as model drugs in an in vitro drug release experiment. All 3 hydrogels significantly prolonged drug release. The release rate of hydrophilic nalbuphine increased in the order CPN相似文献   

Fast-responsive porous thermoresponsive microspheres for controlled delivery of macromolecules

Porous thermoresponsive microspheres with a homogeneous dimension and distribution of the pores are synthesized by an original method. Poly(N-isopropylacrylamide-co-acrylamide) (poly(NIPAAm-co-AAm)) copolymer was obtained as a thermoresponsive material with a lower critical solution temperature (LCST) under physiologic-like conditions (i.e., at 37 °C and pH 7.4, 50 mM phosphate buffer). Semitelechelic oligomers of NIPAAm (ONIPAAm) were also synthesized in the presence of 3-mercaptopropionic acid (MPA) (chain transfer molecule) which acts as a pore-forming agent. Poly(NIPAAm-co-AAm) and ONIPAAm were solubilized in acidified aqueous solution, dispersed in a mineral oil, and transformed in stable microspheres by crosslinking the amide group with glutaraldehyde at temperatures below and above the LCST of the oligomers, and always below the LCST of the polymer. Microspheres obtained at temperatures below the LCST of ONIPAAm are characterized by a homogeneous porous structure with a narrow distribution of the pore size. These microspheres are characterized by a very rapid response rate when the temperature changes below and above the body temperature. The higher is the amount of the porogen in the polymer solution, the larger is the pore size and faster is the response rate. The porous microspheres with suitable pore size are a conveyable matrix for loading and temperature-controlled release of the high molecular weight model drug blue dextran (BD).     

Release of paeonol-β-CD complex from thermo-sensitive poly(N-isopropylacrylamide) hydrogels

By preparing an inclusion complex of paeonol (PAE) with β-cyclodextrin (β-CD), this study investigated its release behavior from thermo-sensitive poly(N-isopropylacrylamide) (PNIPAAm) hydrogels. The PAE-β-CD complex was prepared via coprecipitation. According to differential scanning calorimeter (DSC) and X-ray diffraction (XRD) results, the solid PAE-β-CD complex was found in the amorphous state, indicating that each PAE molecule was encapsulated by a β-CD molecule. The change of chemical shifts of H3 and H5 in proton nuclear magnetic resonance (H NMR) spectra indicated that PAE was inside the CD cavity. PNIPAAm hydrogels containing different cross-linker contents were then synthesized and had a similar lowest critical solution temperature (LCST) of around 33°C. Experimental results of swelling and deswelling indicated that increasing the cross-linker content of the hydrogel decreased the swelling ratio and increased the water retention. According to experimental results of PAE-β-CD complex release, the release rate at 45°C (>LCST) was higher than at 25°C (相似文献   

The delivery of platinum drugs from thermosensitive hydrogels containing different ratios of chitosan

New thermosensitive hydrogels of poly(N-isopropylacrylamide) (PNIPAAm) with chitosan (CPN) were prepared and evaluated for use in the delivery of the platinum drugs, cisplatin and carboplatin. The effects of polymers containing different ratios of chitosan on the physicochemical and drug release characteristics were examined. The sol-gel transition temperature of the hydrogels was determined by differential scanning calorimetry (DSC) and viscometry. Discrepancies in the transition temperature among the various polymer systems were more pronounced when determined by viscosity compared by DSC, with the CPN showing a higher transition temperature than PNIPAAm. The cross-sectional structure and surface topography of the hydrogels were examined by scanning electronic microscopy (SEM) and atomic force microscopy (AFM), respectively. The incorporation of chitosan further increased the entanglement of the hydrogel network. An increase in the chitosan ratio in the polymers (CPN-H) also increased the cross-linking structure. A smoother surface of hydrogel matrices was observed for CPN compared with PNIPAAm. All hydrogels tested significantly reduced drug release compared with an aqueous solution. The release rate of platinum drugs from PNIPAAm was retarded at the late stage. CPN matrices could continuously deliver platinum drugs during the experiment. The rate of release from CPN-H was generally slower than that from hydrogels and had a lower chitosan ratio (CPN-L), presumably due to the more-tortuous pathways in the hydrogels. Thermosensitive hydrogels like those prepared in this study may be a promising carrier for the delivery of platinum drugs, as the drug release can be controlled and sustained using CPN networks.     

Temperature-sensitive poly(N-isopropylacrylamide)/poly(ethylene glycol) diacrylate hydrogel microspheres

Objective

To develop and characterize a new class of temperature-sensitive hydrogel microspheres composed of poly(N-isopropylacrylamide)/poly(ethylene glycol) diacrylate (PNIPAAm/PEG-DA).

Methods

The PNIPAAm/PEG-DA hydrogel microspheres were fabricated in two aqueous systems as a result of polymer/polymer immiscibility. Both PNIPAAm and PEG-DA were used as the precursors; the PEG-DA was also used as a cross-linker for the formation of the hydrogel microspheres. Bovine serum albumin was used as the model protein drug to examine the effects of the thermo-responsive properties of the hydrogel microspheres on the release of a protein at two different temperatures (22°C and 37°C).

Results

The hydrated PNIPAAm/PEG-DA hydrogel microspheres exhibited a swollen diameter of 50µm, with a narrow particle-size distribution. Scanning electron microscopy and environmental scanning electron microscopy observations revealed that, upon swelling, the resulting hydrogel microspheres had a regular spherical and rough surface morphology. The lower critical solution temperature (LCST) of the PNIPAAm/PEG-DA hydrogel microspheres was around 29.1°C, based on differential scanning calorimetric data. The release of BSA from the hydrogel microspheres at 37°C was slower than that at 22°C because of the thermo-responsive nature of PNIPAAm at temperatures above its LCST.

Conclusions

We believe that these kinds of PNIPAAm/PEG-DA hydrogel microspheres may have wide applications as promising drug delivery systems, because of their intelligent nature upon external temperature change.     

Crosslinked hydrogels—a promising class of insoluble solid molecular dispersion carriers for enhancing the delivery of poorly soluble drugs

Water-insoluble materials containing amorphous solid dispersions (ASD) are an emerging category of drug carriers which can effectively improve dissolution kinetics and kinetic solubility of poorly soluble drugs. ASDs based on water-insoluble crosslinked hydrogels have unique features in contrast to those based on conventional water-soluble and water-insoluble carriers. For example, solid molecular dispersions of poorly soluble drugs in poly(2-hydroxyethyl methacrylate) (PHEMA) can maintain a high level of supersaturation over a prolonged period of time via a feedback-controlled diffusion mechanism thus avoiding the initial surge of supersaturation followed by a sharp decline in drug concentration typically encountered with ASDs based on water-soluble polymers. The creation of both immediate- and controlled-release ASD dosage forms is also achievable with the PHEMA based hydrogels. So far, ASD systems based on glassy PHEMA have been shown to be very effective in retarding precipitation of amorphous drugs in the solid state to achieve a robust physical stability. This review summarizes recent research efforts in investigating the potential of developing crosslinked PHEMA hydrogels as a promising alternative to conventional water-soluble ASD carriers, and a related finding that the rate of supersaturation generation does affect the kinetic solubility profiles implications to hydrogel based ASDs.KEY WORDS: Amorphous solid dispersions, Crosslinked hydrogels, Poly(2-hydroxyethylmethacrylate), Supersaturation, Kinetic solubility     

Improving the loading and release of NSAIDs from pHEMA hydrogels by copolymerization with functionalized monomers

Poly(hydroxyethyl methacrylate), pHEMA, hydrogels are widely used for preparing implants, contact lenses, and other biomedical devices, which in many circumstances should load drugs to deliver them in the adjacent tissues. To enhance the potential of pHEMA hydrogels as nonsteroidal anti-inflammatory drugs (NSAIDs) delivery systems, 4-vinyl-pyridine (VP) and N-(3-aminopropyl) methacrylamide (APMA) were incorporated to the network (25-150 mM). The incorporated monomers did not change the viscoelastic properties neither the state of water, but remarkably increased the amount of ibuprofen (up to 10-fold) and diclofenac (up to 20-fold) loaded. Dried loaded pHEMA-APMA and pHEMA-VP hydrogels quickly swelled in water but ionic/hydrophobic interactions prevented the amount of drug released to be above 10%. By contrast, once the water-swollen hydrogels were transferred to pH 5.8 or 8.0 phosphate buffers or NaCl solutions, the release was prompted by competition with ions of the medium. The remaining of hydrophobic interactions and the high polymeric density of the pHEMA hydrogels contributed to sustain the release process for at least 24 h for ibuprofen and almost 1 week for diclofenac. The release rate was independent of the salt content and pH in the physiological range of values, which enables the design of hydrogel-based delivery systems with predictable release rate.     

Novel PLA modification of organic microcontainers based on ring opening polymerization: synthesis, characterization, biocompatibility and drug loading/release properties

In the current study, poly lactic acid (PLA) modified hollow crosslinked poly(hydroxyethyl methacrylate) (PHEMA) microspheres have been prepared, in order to obtain a stimulus-responsive, biocompatible carrier with sustained drug release properties. The synthetical process consisted of the preparation of poly(methacrylic acid)@poly(hydroxyethyl methacrylate-co-N,N'-methylene bis(acrylamide)) microspheres by a two stage distillation-precipitation polymerization technique using 2,2'-azobisisobutyronitrile as initiator. Following core removal, a PLA coating of the microspheres was formed, after ring opening polymerization of DL-lactide, attributing the initiator's role to the active hydroxyl groups of PHEMA. The anticancer drug daunorubicin (DNR) was selected for the study of loading and release behavior of the coated microspheres. The loading capacity of the PLA modified microspheres was found to be four times higher than that of the parent ones (16% compared to 4%). This coated microspherical carrier exhibited a moderate pH responsive drug release behavior due to the pH dependent water uptake of PHEMA, and PLA hydrolysis. The in vitro cytotoxicity of both the parent and the DNR-loaded or empty modified hollow microspheres has been also examined on MCF-7 breast cancer cells. The results showed that although the empty microspheres were moderately cytotoxic, the DNR-loaded microspheres had more potent anti-tumor effect than the free drug. Therefore, the prepared coated microspheres are interesting drug delivery systems.     

Thermosensitive Hydrogels Composed of Hyaluronic Acid and Gelatin as Carriers for the Intravesical Administration of Cisplatin

The aim of this work was to evaluate the use of thermosensitive hydrogels for intravesical cisplatin delivery into the bladder. Poly(N-isopropylacrylamide) (PNIPAM) was grafted onto hyaluronic acid (HA) to synthesize an HPN copolymer, which was further grafted with gelatin to form an HPNG copolymer. A 3% concentration of HPN and HPNG was sufficient to exert a thermosensitive response, whereas a concentration of 8% was needed for PNIPAM to form the hydrogel. The physicochemical and drug delivery properties were examined by scanning electron microscopy (SEM), the lower critical solution temperature (LCST), hydration ratio, and in vitro cisplatin release. The incorporation of HA and gelatin produced a different microstructure compared to the parent PNIPAM hydrogel. Gelatin conjugation increased the fibrous structure in the matrix. The LCSTs of PNIPAM, HPN, and HPNG were 32.3, 32.0, and 30.7°C, respectively. The copolymers showed an eightfold increase in the hydration capacity compared to PNIPAM, with no significant difference in values between HPN and HPNG. The release of cisplatin from an aqueous solution (control) was nearly complete after 8 h, compared to 85, 80, and 52% release from PNIPAM, HPN, and HPNG, respectively. In vivo evaluation of cisplatin levels in bladder tissues was performed following intravesical instillation in rats. When the dwell time was extended to 6 h, PNIPAM showed a sevenfold enhancement in the drug concentration in the bladder wall. HPNG also showed a twofold increase in the drug concentration. The administration of cisplatin by the HPN carrier did not change the drug accumulation compared to the control. Confocal laser scanning microscopic results confirmed the trend of drug absorption from various systems. A histological examination showed no adverse change in the urothelium with HPN or HPNG application. PNIPAM caused partial desquamation of umbrella cells. The thermosensitive hydrogels prepared in this study may be promising carriers for targeted drug delivery to the bladder.     

Release kinetics of benzoic acid and its sodium salt from a series of poly(N-isopropylacrylamide) matrices with various percentage crosslinking

Swelling and concomitant drug-release kinetics from a series of poly(N-isopropylacrylamide) (PNIPA) matrices were examined. Scanning electron microscopy indicated a decrease in polymer pore/mesh size above the lower critical solution temperature (LCST) with increasing percentage crosslinker. The release of sodium benzoate (NaB) or benzoic acid (BA) were investigated above and below the LCST of the gels and compared to the drug-loaded gel-swelling rates. The release rate of NaB increased with increasing percentage crosslinker above the LCST in contrast to a decrease in release rate with increasing crosslinker seen previously with non-thermoresponsive hydrogel systems. As the percentage crosslinker increased, there was therefore a decrease in the ability to thermally control the release of this small model drug. In contrast to the crosslinker-dependent pattern apparent with NaB, drug-PNIPA hydrophobic binding controlled the swelling rate of BA-loaded hydrogels. As a result, all the BA-loaded systems showed similar diffusion controlled swelling and release patterns, effectively independent of the inherent-swelling rates of the hydrogels. The crosslinking content of the hydrogel and the physicochemical nature of the loaded drug were therefore shown to be important in thermal control of drug release from PNIPA hydrogels.     

Effect of some physiological and non-physiological compounds on the phase transition temperature of thermoresponsive polymers intended for oral controlled-drug delivery.

Poly-N-isopropylacrylamide (PNIPAAm) thermosensibility makes this polymer a very attractive candidate for controlled drug delivery systems. The polymer possesses a lower critical solution temperature (LCST) which was found to be around 32 degrees C in pure water, but which can be affected by the medium composition, i.e. presence of salts or surfactants. The knowledge of the effects of such substances on the LCST is very important while using PNIPAAm as a controlled drug delivery agent. The influence of a number of physiological and non-physiological salts and surfactants has been studied. The results obtained show that the addition of salts provokes an important decrease of the LCST of the polymer (salting out effect). A strong influence of the valence and of the size of the anions of the halide group was found. As to the surfactants, according to their type and concentration, a decrease or an increase of the LCST or even no effect at all were found. The effect of the GI secretions on the PNIPAAm phase separation temperature is also discussed.     

温敏水凝胶Dex-PCL-HEMA/PNIPAAm的生物学性能

目的:对温度敏感水凝胶葡聚糖接枝聚己内酯-甲基丙烯酸羟乙酯共聚N-异丙基丙烯酰胺(Dex-PCL-HEMA/PNIPAAm)合成及体外降解进行研究,了解水凝胶的体外生物学性能.方法:利用自由基聚合法合成Dex-PCL-HEMA/PNIPAAm,并对其作LCST的测定、内部形貌观察、体外降解、体外控制释放胎牛血清蛋白(BSA).结果:水凝胶的较低临界溶解温度(LCST)为33.2～34.2℃;内部形貌观察到水凝胶的孔径随着Dex-PCL-HEMA的含量的增大而缩小;体外酶降解显示DN水凝胶在前3天降解比较快,在第4～16天间,DN1、DN2、DN3、DN4四种水凝胶的降解率依次增大,16天后基本上不再降解;DN Dex-PCL-HEMA/PNIPAAm凝胶体外释放BSA曲线显示前5小时内释放最快,此后逐渐减慢.结论:Dex-PCL-HEMA/PNIPAAm水凝胶保持了其良好的温度敏感性,体外实验显示生物相容性良好,因此可以作为动物实验的材料.     

Surface crosslinking for delayed release of proxyphylline from PHEMA hydrogels

Delayed release systems find applications in chronotherapeutics and colon-specific delivery. They have also been considered suitable carriers for the oral delivery of peptides and proteins. In prior work, our research group has reported surface crosslinking as an effective technique to modify drug release profiles for poly(vinyl alcohol) (PVA) hydrogels, reducing the early burst effect in particular. Here, we demonstrate the feasibility of delayed release of proxyphylline from poly(2-hydroxyethyl methacrylate) (PHEMA) hydrogels via surface crosslinking. Studies on in vitro drug release and the morphology changes of PHEMA hydrogels during swelling and drug release showed that the highly surface crosslinked layers and the ruptures occurring in these layers during swelling were likely responsible for the delayed release. In addition, the initial burst was significantly reduced or even eliminated from the drug release profile for PHEMA to achieve near zero-order release by judicious selection of two surface crosslinking parameters: crosslinking reagent concentration and exposure time used for the surface crosslinking treatment.     

Investigation of Temperature-Responsive Tocosomal Nanocarriers as the Efficient and Robust Drug Delivery System for Sunitinib Malate Anti-Cancer Drug: Effects of MW and Chain Length of PNIPAAm on LCST and Dissolution Rate

In this study, for the first time, the coated tocosome by blend of chitosan, CS, and poly(N-isopropylacrylamide), PNIPAAm, was developed as the efficient and robust drug delivery system with improved drug encapsulation efficiency, extended stability, proper particle size and industrial upscaling for Sunitinib malate anti-cancer drug. Tocosome was synthesized by using Mozafari method as a scalable and robust method and without the need for organic solvents. The effects of tocosome composition and drug concentration on the stability, particle size of tocosome, zeta potential, encapsulation efficacy and loading of drug into it were investigated by Taguchi method, and optimum composition was selected for combining with the polymeric blend. Homopolymer of PNIPAAm was synthesized by two different polymerization methods, including free radical and reversible addition–fragmentation chain transfer (RAFT). Effects of molecular weight (MW) and chain length of the polymers on lower critical solution temperature (LCST) were examined. The developed nanocarrier in this research, CS-Raft-PNIPAAm-tocosome, indicated LCST value beyond 37°C (about 45°C) and this is suitable for hyperthermia and spatio-temporal release of drug particles.     

Progestin permeation through polymer membranes III: Polymerization solvent effect on progesterone permeation through hydrogel membranes.

Hydrogels prepared from poly(hydroxyethyl methacrylate) are biocompatible and highly permeable to low molecular weight solutes. Permeation rates can be varied by altering the cross-linker concentration or using copolymers; the latter are chosen to alter the hydrogel equilibrium hydration. These factors suggest that hydrogels are good candidates for controlled-release drug delivery devices. Hydrogels may be synthesized using various temperatures, initiators (nature and concentration), and solvents (nature and concentration). This study demonstrated that progesterone permeation through poly(hydroxyethyl methacrylate) films is independent of polymerization solvent (nature and concentration) for the solvents, water, ethanol, and tert-butyl alcohol. The importance of hydrogel equilibrium hydration in progesterone permeation is emphasized.     

Drug release characteristics of physically cross-linked thermosensitive poly(N-vinylcaprolactam) hydrogel particles

The effect of physical cross-linking was studied on the formation and properties of thermosensitive polymer particles of poly(N-vinylcaprolactam), PVCL, and PVCL grafted with poly(ethylene oxide) macromonomer, PVCL-graft-C(11)EO(42). Loading and release of model drugs into/from the hydrogel particles were evaluated. Thermosensitive particles were stabilized by cross-linkers, the most feasible of which was salicylic acid (SA). At 23 degrees C, below the lower critical solution temperature (LCST) of the thermosensitive polymers, stability of the hydrogels was poor, whereas at 37 degrees C stable hydrogel particles were formed. All the drugs and also the cross-linker (SA) were released more efficiently from the PVCL particles compared to the PVCL-graft-C(11)EO(42) particles. Drug concentration and pH affected clearly the rate and extent of drug release in physiological buffer. The higher drug release from the PVCL was based on the more open gel-like structure as opposed to PVCL-graft-C(11)EO(42) particles. Complex formation between the cross-linker and the polymers was due to the hydrogen bonding between the hydroxyl groups of SA and H-bond acceptors of the PVCL. In the case of PVCL-graft-C(11)EO(42), the ethylene oxide chain provided more opportunities for H-bonding in comparison to the pure PVCL, creating more stable complexes (more tightly packed particles) leading to sustained drug release.     

Preparation and release of model drugs from thermally sensitive poly(N-isopropylacrylamide) based macrospheres

Emulsion polymerization was employed to prepare poly(N-isopropylacrylamide) hydrogel spheres, which exhibited an LCST of 32 degrees C. The hydrogels were loaded with model drugs (benzoic acid (BA), sodium benzoate and diltiazem HCl (DHCl)) and release investigated at 25 degrees C and 37 degrees C. The temperature at which gel formation occurred was vital for successful hydrogel preparation, macrosphere formation not occurring when the temperature was close to the LCST. Sphere size increased on decreasing the stirring rate and on slowing the rate of addition of the aqueous phase. Pulsatile delivery was investigated using BA and DHCl. For both compounds a pulse was observed with a change in temperature. Pulsed release of the smaller model drug of lowest solubility, BA, was more successful. Drug release from hydrogel spheres was, therefore, found to be dependent on the physicochemical properties of the drugs, with pulsatile release of low molecular weight compounds, by temperature cycling, difficult to control.     

Evaluation of a new controlled-drug delivery concept based on the use of thermoresponsive polymers

The purpose of this work is to develop a new delivery concept making a thermosensitive polymer based on poly(N-isopropylacrylamide) (PNIPAAm) useful as a time-controlled drug release device, without any temperature changes of the dissolution medium. It was previously found that some salts induce a decrease of the polymer lower critical solution temperature (LCST). Use is here made of that property to show that salt concentration variations can be used as a substitute for temperature changes to make the polymer coating of compression-coated tablets soluble or insoluble, consequently creating a possible new concept of drug delivery control from delivery systems containing thermoresponsive polymers. The obtained results show the influence of the type and amount of salts incorporated into compression-coated tablets on the release lag time of a model drug.     

Fluxgate magnetorelaxometry: A new approach to study the release properties of hydrogel cylinders and microspheres

Hydrogels are under investigation as long term delivery systems for biomacromolecules as active pharmaceutical ingredients. The release behavior of hydrogels can be tailored during the fabrication process. This study investigates the applicability of fluxgate magnetorelaxometry (MRX) as a tool to characterize the release properties of such long term drug delivery depots. MRX is based on the use of superparamagnetic core-shell nanoparticles as model substances. The feasibility of using superparamagnetic nanoparticles to study the degradation of and the associated release from hydrogel cylinders and hydrogel microspheres was a major point of interest. Gels prepared from two types of photo crosslinkable polymers based on modified hydroxyethylstarch, specifically hydroxyethyl starch-hydroxyethyl methacrylate (HES-HEMA) and hydroxyethyl starch-polyethylene glycol methacrylate (HES-P(EG)(6)MA), were analyzed. MRX analysis of the incorporated nanoparticles allowed to evaluate the influence of different crosslinking conditions during hydrogel production as well as to follow the increase in nanoparticle mobility as a result of hydrogel degradation during release studies. Conventional release studies with fluorescent markers (half-change method) were performed for comparison. MRX with superparamagnetic nanoparticles as model substances is a promising method to analyze pharmaceutically relevant processes such as the degradation of hydrogel drug carrier systems. In contrast to conventional release experiments MRX allows measurements in closed vials (reducing loss of sample and sampling errors), in opaque media and at low magnetic nanoparticle concentrations. Magnetic markers possess a better long-term stability than fluorescent ones and are thus also promising for the use in in vivo studies.     

Hydrogel Containing Silica Shell Cross-Linked Micelles for Ocular Drug Delivery

Poly(2-hydroxyethyl methacrylate–methacrylic acid–ethylene glycol dimethacrylate) hydrogels loaded with silica shell cross-linked methoxy(polyethylene glycol)-block-polycaprolactone (MePEG-b-PCL) micelles with rod-like morphology were prepared as a potential soft contact lens material for the sustained release of ocular drugs. The silica shell cross-linked methoxy micelles (SSCMs) comprising a polycaprolactone core surrounded by a silica shell were synthesized and their size, morphology, stability, and drug release kinetics were evaluated. The relationships between the composition of the SSCM-loaded poly(2-hydroxyethyl methacrylate) (pHEMA)-based hydrogels and their transparency, surface wettability, and equilibrium water content were determined. Scanning electron microscopy (SEM) images of SSCM–hydrogel systems showed the presence of intact SSCMs within the hydrogel matrix. Dexamethasone acetate (DMSA), a hydrophobic ophthalmic drug, was loaded into the SSCMs prior to their incorporation into the hydrogels. In vitro release of DMSA from the SSCM–hydrogels, with varying drug loading levels, was observed for up to 30 days. Overall, the incorporation of rod-like SSCMs within pHEMA-based hydrogels provided sustained release over prolonged periods while maintaining optical transparency. This delivery system may be suitable for use as a therapeutic soft contact lens material.