A Four-Step Purification Process for Gag VLPs: From Culture Supernatant to High-Purity Lyophilized Particles
Bibliographic record
Abstract
Gag-based virus-like particles (VLPs) have high potential as scaffolds for the development of chimeric vaccines and delivery strategies. The production of purified preparations that can be preserved independently from cold chains is highly desirable to facilitate distribution and access worldwide. In this work, a nimble purification has been developed, facilitating the production of Gag VLPs. Suspension-adapted HEK 293 cells cultured in chemically defined cell culture media were used to produce the VLPs. A four-step downstream process (DSP) consisting of membrane filtration, ion-exchange chromatography, polishing, and lyophilization was developed. The purification of VLPs from other contaminants such as host cell proteins (HCP), double-stranded DNA, or extracellular vesicles (EVs) was confirmed after their DSP. A concentration of 2.2 ± 0.8 × 109 VLPs/mL in the lyophilized samples was obtained after its storage at room temperature for two months. Morphology and structural integrity of purified VLPs was assessed by cryo-TEM and NTA. Likewise, the purification methodologies proposed here could be easily scaled up and applied to purify similar enveloped viruses and vesicles.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.001 | 0.001 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".