Systemic UOX Delivery Attack Surface¶
The target is not “make oral UOX work.” It is to identify delivery vulnerabilities that could place active UOX where it can alter urate biology, then test the cheapest discriminating experiment for each route.
Two hypotheses must remain separate:
- Luminal UOX: the enzyme remains outside the bloodstream and degrades urate in the gut. Animal evidence supports the mechanism, while human effect size, dose, topology, and safety remain open.
- Systemic or local-tissue UOX: the enzyme reaches blood or a defined tissue compartment. Existing injected uricases establish that systemic enzyme replacement can work, but immunogenicity, infusion reactions, persistence, and route-specific safety remain central constraints.
Evidence for one route does not validate the other.
Red-team map¶
| Attack surface | Exploit hypothesis | Evidence boundary | Cheapest decisive gate |
|---|---|---|---|
| Established parenteral delivery | IV or SC delivery bypasses epithelial barriers. | Approved and clinical uricases establish systemic pharmacology for their own products. Clinical Trial. They do not transfer formulation, persistence, or immune behavior to a new construct. | Characterize active product, PK, anti-drug antibodies, infusion/injection reactions, and peroxide handling in an appropriate preclinical program. |
| Intra-articular delivery | Place UOX near a crystal-bearing joint or tophus while controlling local peroxide. | Local UOX/catalase work is preclinical; comp-035 is non-decision-grade. Animal Model + Mechanistic Extrapolation. | Matched reaction-site H₂O₂ time course, catalase activity/stoichiometry, retention, local exposure, and tissue safety. |
| Transdermal devices | Microneedles, iontophoresis, sonophoresis, or jet systems may bypass the gut. | Protein-delivery precedent is cargo- and device-specific. Mechanistic Extrapolation for UOX. | Measure delivered active tetramer, local injury, sterility, systemic PK, and immunogenicity using a manufactured research formulation. |
| Nasal, pulmonary, buccal, or rectal mucosa | A thinner or less proteolytic mucosa may permit protein transport. | Small-peptide or other-protein precedents do not establish transport of active UOX. Mechanistic Extrapolation. | Bidirectional tissue/transwell flux with active-UOX recovery, barrier-integrity, histology, and local toxicity controls. |
| Intestinal permeation enhancement | Tight-junction or transcellular enhancers might increase uptake. | Enhancer performance is size-, formulation-, tissue-, and exposure-dependent; barrier opening can itself create safety risk. Mechanistic Extrapolation. | Human-relevant intestinal model measuring active basolateral UOX, TEER recovery, permeability markers, cytokines, and tissue injury. |
| Receptor- or cell-mediated transcytosis | FcRn, M cells, CPPs, or targeted nanoparticles may carry UOX across epithelium. | Uptake is not equivalent to intact basolateral release; endosomal trapping and cargo damage remain open. Mechanistic Extrapolation. | Directional transport assay with receptor perturbation, intact-mass/activity readout, endosomal-fate analysis, and barrier-safety controls. |
| Vesicles and ingestible devices | Exosomes, OMVs, or mechanical injectors may protect cargo or cross a barrier. | Delivery-class precedents do not establish UOX loading, release, activity, endotoxin safety, or systemic exposure. Mechanistic Extrapolation. | Cargo identity/activity before and after delivery, release site, barrier integrity, innate-immune activation, and PK. |
| Nucleic-acid delivery | mRNA or gene transfer could make host cells produce UOX. | Platform precedents exist, but UOX expression, secretion, immune response, duration, and reversibility require a dedicated program. Mechanistic Extrapolation. | Cell-type expression/localization, active-enzyme output, coproduct/peroxide handling, biodistribution, reversibility, and immune safety. |
No route is ranked by convenience, presumed bioavailability, or do-it-yourself feasibility. Cross-route prioritization belongs in the delivery route matrix.
Shared failure modes¶
Active oligomer does not survive delivery¶
Detecting UOX antigen or cargo uptake is insufficient. The readout must recover active enzyme in the target compartment and characterize oligomerization, aggregation, and degradation.
Peroxide becomes the limiting toxicity¶
UOX activity and H₂O₂ generation are coupled. Measure scavenger capacity at the reaction site, not only bulk formulation catalase or a modeled concentration.
Barrier disruption overwhelms the benefit¶
Permeation enhancers and physical devices can create epithelial or tissue injury, inflammation, infection risk, and variable exposure. Barrier recovery and local safety are co-primary endpoints.
Immune exposure changes with route¶
Keeping UOX luminal, placing it locally, and exposing it systemically create different immune questions. Food-use history or oral non-absorption cannot support a systemic immunogenicity claim.
A monomer or fusion loses function¶
Smaller cargo may cross more readily but may not retain the required UOX assembly or activity. Test the actual engineered construct; do not infer function from molecular size.
Experimental ladder¶
- Product identity: exact sequence, active oligomer, impurities, aggregation, activity, substrate response, oxygen dependence, and peroxide.
- Route-specific in-vitro model: transport or depot behavior plus active-UOX recovery and local safety.
- Mechanism control: receptor block, enhancer-free control, inactive UOX, or device-only control appropriate to the route.
- Ex-vivo tissue: intact tissue transport, retention, barrier recovery, and histology where informative.
- Preclinical translation: PK/PD, local and systemic safety, immunogenicity, and repeat exposure under an approved protocol.
- Human study: only after product, preclinical, regulatory, ethics, and monitoring gates support it.
No personal sourcing, self-administration, serum-before/after experiment, or home device path follows from this research map.
Portfolio decision rule¶
A route advances when it delivers reproducible active UOX to the intended compartment with a credible safety and repeat-exposure profile. A route is redirected or killed when transport destroys activity, exposure is too variable, peroxide or tissue injury dominates, or the formulation/device burden exceeds the value of the exploit.
Failure of a systemic route does not invalidate the luminal sink; failure of luminal UOX does not invalidate local or systemic enzyme replacement. Each track updates only the claims it actually tests.