Compact Scaffolds │ Microbial Speed │ Clinical-Grade Quality
Antibody fragments—Fabs, scFvs, diabodies, and single-domain VHH nanobodies—deliver full antigen specificity in a fraction of the molecular weight of whole IgG. Their small size drives rapid tissue penetration, enables inhaled and topical delivery, and simplifies recombinant expression in microbial hosts. Elise Biopharma has built a dedicated antibody-fragment platform that unites synthetic-biology design, high-throughput microbial screening, and GMP manufacturing to take these versatile molecules from DNA construct to commercial lot without ever leaving our campus.
Molecular Design & Candidate Optimisation
Our discovery engineers begin by analysing paratope architecture, stability liabilities, and developability flags across hundreds of in-silico variants.
- Structure-guided humanisation eliminates framework immunogenicity while preserving CDR geometry.
- Rational dimerisation control converts scFv monomers into diabodies or triabodies by manipulating linker length and orientation, boosting avidity without increasing aggregation risk.
- VHH & nanobody libraries—derived from immune, naïve, or synthetic repertoires—are mined by yeast or phage display at pM to nM affinities, then reformatted as mono-, bi- or tri-specific fusions.
- Affibody-like scaffolds and Fc-free half-life extension tags (albumin binders, PASylation) are appended, if required, to hit pre-clinical PK targets while maintaining the low-viscosity benefits of small fragments.
All variants pass a developability gauntlet—AggScore, charge distribution, pI spread, and predicted viscosity—so the construct that reaches the fermentor is primed for manufacturability.
High-Yield Microbial Expression
Strain & Vector Engineering
- Codon-optimised, secretion-signal vectors direct fragments to the E. coli periplasm or Pichia secretome, exploiting native oxidising environments for correct disulphide pairing.
- CRISPR chassis edits up-regulate DsbC/DsbG foldases and knock out proteases that clip C-terminal regions, boosting soluble yield by up to 3-fold.
- Auto-induction protocols minimise labour and acetate accumulation, crucial for toxic or highly basic VHHs.
Smart Fermentation Control
Video-rate Raman probes track lactose/inducer uptake, dissolved oxygen, and overflow metabolites, while digital twins predict oxygen transfer and pH drift during scale-up. As a result, titres established at 20 L routinely reproduce ±8 % at 2 000 L without re-optimisation.
Downstream Purification Tailored to Small Scaffolds
Fragment purification demands gentle yet discriminating unit operations:
- Dual-mode capture couples IMAC for His-tag removal with protein-L or Camelid VHH affinity adsorbents when epitope integrity is mission-critical.
- Hydrophobic-interaction polishing strips endotoxin and low-level truncations that co-elute during ion-exchange.
- Dia-filtration & concentration in 5–10 kDa TFF cassettes maintains recovery >92 % while delivering <0.05 EU mg⁻¹ endotoxin—meeting parenteral and inhalation thresholds.
For nanobodies destined for nebulisers or dry-powder inhalers, ultrafiltration cycles are tailored to achieve final osmolality and surfactant profiles that prevent shear-induced aggregation during aerosolisation.
Analytical & Biofunctional Excellence
Potency and safety metrics are embedded into every development gate:
- SPR/BLI kinetic panels confirm sub-nM affinities and dual-specific engagement for biparatopic constructs.
- SEC-MALS and DLS track monomer content and hydrodynamic radius—critical for renal-clearance prediction.
- Cell-based functional assays (e.g., T-cell engagement for BiTE-like diabodies, neutralisation for anti-cytokine VHHs) correlate bioactivity with structural CQAs.
- Residual DNA, HCP, and endotoxin testing is harmonised with Elise’s recombinant-protein and cytokine platforms, streamlining multi-modal submissions.
GMP Manufacturing & Fill-Finish
Our ISO 5 microbial suites, 2 000 L single-use fermentors, and robotic isolator fill-finish lines support clinical and commercial supply in vial, PFS, or RTU-cartridge formats. Electronic batch records tie every critical parameter—bioreactor PID loops, chromatography UV profiles, filter-integrity tests—directly to the lot Certificate of Analysis, simplifying regulatory review.
Why Elise for Fragments & Nanobodies?
- Microbial mastery – 6–12 g L⁻¹ soluble scFv yields, 3–6 g L⁻¹ VHH yields with downstream recovery >70 %.
- Speed – Feasibility data in six weeks; GMP drug substance in 9–12 months.
- Dual compliance – Single infrastructure meets cGMP for therapeutics and ISO 13485 for diagnostic VHH reagents.
- Format versatility – Fab, scFv, diabody, triabody, nanobody, and fusion tags handled under one process umbrella.
- Integrated analytics – On-site HR-MS, epitope binning, and cell-based potency eliminate out-sourced bottlenecks.
Move Faster with Smaller Antibodies
If your programme calls for agile, high-affinity scaffolds—or you need kg-scale nanobody supply under a single quality system—Elise Biopharma is your partner of choice.