Enhancing Drug Release From Antibiotic-loaded Bone Cement Using Porogens

Current antibiotic-loaded bone cement formulations face limitations in drug release rates. While PMMA-based cements are widely used in orthopedic surgery, their ability to deliver antibiotics over time remains suboptimal. Prior research has shown that porosity influences drug elution. However, the impact of different porogen types on this process remains unclear. This gap motivated a detailed investigation into how porogen selection affects drug release profiles. No prior work had resolved whether gelatin sponges or ceramic granules offer superior elution rates. The field lacks comparative data on porogen efficacy in PMMA matrices. Researchers have yet to determine whether porosity size correlates with drug release efficiency. This study aims to address these uncertainties by evaluating two porogen types.

The study aimed to assess whether adding porogens to PMMA improves antibiotic elution rates. Specifically, it sought to compare the effects of gelatin sponges and ceramic granules. The researchers focused on gentamicin-loaded PMMA as a model system. They hypothesized that porosity would influence drug release dynamics. The study tested whether porogen concentration affects elution rates. It also examined how porogen type impacts pore size and mechanical properties. The goal was to identify the most effective porogen for drug delivery. This work builds on prior findings about porosity and drug diffusion.

The researchers prepared PMMA samples with varying concentrations of two porogens. Gelatin sponges (Spongostan) and ceramic granules (Bicera) were used. Each porogen was added at increasing concentrations to gentamicin-loaded PMMA. The samples were analyzed for porosity using FTIR spectroscopy. Scanning electron microscopy provided structural insights. Young's modulus measurements assessed biomechanical properties. Drug elution was quantified using OPA assays at multiple timepoints. The study compared elution rates across porogen types and concentrations.

Spongostan significantly increased drug release rates compared to Bicera. At higher concentrations, Spongostan showed a 5.65-fold improvement in elution efficiency. Bicera improved elution by 3.75-fold under the same conditions. The highest elution rate was observed in G3 samples. Pore sizes in Spongostan samples ranged from 70 to 200 μm. Bicera samples had smaller pores, measuring 5 to 10 μm. Spongostan's larger pores correlated with higher elution rates. However, Spongostan reduced the biomechanical strength of PMMA.

The addition of porogens enhances drug elution from PMMA-based bone cement. Spongostan outperformed Bicera in terms of elution efficiency. Larger pores in Spongostan samples facilitated faster drug release. However, this came at the cost of reduced mechanical strength. Bicera also improved elution but to a lesser extent. The study confirms that porogen type influences drug release rates. These findings suggest that porogen selection is critical for optimizing drug delivery. The authors propose that porogen type should be considered in cement formulation.