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The growing demand for viral vectors as nanoscale therapeutic agents in gene therapy necessitates efficient and scalable purification methods. This study examined the role of nanoscale biomaterials in optimizing viral vector clarification through a model system mimicking real AAV2 crude harvest material. Using lysed HEK293 cells and silica nanoparticles (20 nm) as surrogates for AAV2 crude harvest, we evaluated primary (depth filters) and secondary (membrane-based) filtration processes under different process parameters and solution conditions. These filtration systems were then assessed for their ability to recover nanoscale viral vectors while reducing DNA (without the need for endonuclease treatment), protein, and turbidity. Primary clarification demonstrated that high flux rates (600 LMH) reduced the depth filter’s ability to leverage adsorptive and electrostatic interactions, resulting in a lower DNA removal. Conversely, lower flux rates (150 LMH) enabled >90% DNA reduction by maintaining these interactions. Solution conductivity significantly influenced performance, with high conductivity screening electrostatic interactions, and the model system closely matching real system outcomes under these conditions. Secondary clarification highlighted material-dependent trade-offs. The PES membranes achieved exceptional AAV2 recovery rates exceeding 90%, while RC membranes excelled in DNA reduction (>80%) due to their respective surface charge and hydrophilic properties. The integration of the primary clarification step dramatically improved PES membrane performance, increasing the final flux from ~60 LMH to ~600 LMH. Fouling analysis revealed that real AAV2 systems experienced more severe and complex fouling compared to the model system, transitioning from intermediate blocking to irreversible cake layer formation, which was exacerbated by nanoscale impurities (~10–600 nm). This work bridges nanomaterial science and biomanufacturing, advancing scalable viral vector purification for gene therapy. 

Abstract Metal‐coordinated hydrogels can form a percolated network with transient bonds due to metal ions‐functional group coordination. Each metal ion can link with more than one ligand, leading to intricate speciation of bonding modes. While the mechanics of transient gels made with four‐arm polymers are often studied, less is known about how increasing the number of arms affects the modulus. Using shear rheology, the modulus of hydrogels prepared from four‐, six‐, and eight‐armed poly(ethylene glycols), functionalized with histidine ligands that complex with nickel (II) ions is measured. These gels have matched polymer wt.% and varied pH to compare their moduli. It is considered whether the modulus can be described by established polymer network models by calculating the speciation of metal‐coordinated cross‐links and then incorporating it into a phantom network prediction. This study finds that 1) increasing the number of polymer arms increases the modulus, 2) the phantom network allows reasonable modulus approximation for four‐arm and six‐arm gels, and 3) the modulus of eight‐arm gels exceeds the phantom network prediction. Since polymer cores act as chemical cross‐links and metal‐coordinated cross‐links form network strands, it is possible that increasing the number of metal‐coordinated linkages per molecule reinforces the chemical cross‐link at the polymer core. 

Abstract The ability to direct cell behavior has been central to the success of numerous therapeutics to regenerate tissue or facilitate device integration. Biomaterial scientists are challenged to understand and modulate the interactions of biomaterials with biological systems in order to achieve effective tissue repair. One key area of research investigates the use of extracellular matrix‐derived ligands to target specific integrin interactions and induce cellular responses, such as increased cell migration, proliferation, and differentiation of mesenchymal stem cells. These integrin‐targeting proteins and peptides have been implemented in a variety of different polymeric scaffolds and devices to enhance tissue regeneration and integration. This review first presents an overview of integrin‐mediated cellular processes that have been identified in angiogenesis, wound healing, and bone regeneration. Then, research utilizing biomaterials are highlighted with integrin‐targeting motifs as a means to direct these cellular processes to enhance tissue regeneration. In addition to providing improved materials for tissue repair and device integration, these innovative biomaterials provide new tools to probe the complex processes of tissue remodeling in order to enhance the rational design of biomaterial scaffolds and guide tissue regeneration strategies.