The purpose of this study is to determine whether poly（β-amino ester）(PAE)hydrogel loaded with tRNA-derived fragments-antisense oligonucleotides-exosomes(tRF-ASO-Exo) could alleviate symptoms in patients with diabetic ocular surface diseases(DOSD).

Diabetes mellitus is a highly prevalent, chronic systemic metabolic disorder affecting populations worldwide. According to the most recent data from the International Diabetes Federation (IDF), the global prevalence of diabetes among adults stands at 10.5%, whereas in China, it reaches 11.6%-corresponding to approximately 113.9 million affected adults, the highest absolute number globally. Diabetes-related systemic and ocular complications significantly impair patients' quality of life and impose substantial economic burdens on individuals, families, and healthcare systems, thereby constituting a pressing public health challenge requiring coordinated national and international action. Diabetic ocular surface disease (DOSD) represents one of the earliest and most frequently observed ocular complications of diabetes, often preceding other diabetic eye manifestations. Its incidence rises markedly with longer disease duration and suboptimal glycemic control. Notably, diabetic patients undergoing common ophthalmic procedures-including phacoemulsification for cataract, pterygium excision, and vitreoretinal surgery-are at heightened risk of postoperative keratoconjunctival disorders, which may progress to irreversible visual impairment or blindness, thereby threatening long-term ocular integrity. Among individuals with diabetes of ≥5 years' duration, over 60% develop moderate-to-severe dry eye or keratoconjunctival epithelial damage, clinically characterized by progressive symptoms including ocular dryness, foreign body sensation, photophobia, pain, and, in advanced cases, vision loss-collectively resulting in marked functional and quality-of-life deterioration.

Current clinical management of DOSD remains largely palliative, relying predominantly on artificial tear supplementation, secretagogues, and topical anti-inflammatory agents. However, these interventions do not address underlying neuroepithelial dysfunction and are limited by poor long-term adherence-reported rates fall below 50%-leading to suboptimal therapeutic outcomes. Consequently, the development of mechanism-targeted, disease-modifying therapies for DOSD is an urgent unmet clinical need.

Antisense oligonucleotides (ASOs) are synthetic, single-stranded RNA molecules designed to bind complementary tRNA-derived fragments (tRFs) with high specificity, thereby inhibiting their pathogenic activity. ASO-based therapeutics have demonstrated robust efficacy in neurodegenerative disorders, with several candidates having advanced to late-stage clinical trials. Engineered exosomes represent a next-generation drug delivery platform, offering enhanced nucleic acid loading capacity, improved pharmacokinetic stability, increased bioavailability, and superior tissue targeting compared with conventional exosomes or free small-molecule drugs. In ophthalmology, scalable production of engineered exosomes has opened new avenues for localized treatment of keratoconjunctival diseases. Furthermore, hydrogels provide physical encapsulation of nucleic acid therapeutics, shielding them from rapid enzymatic degradation in vivo; when combined with the intrinsic lipid bilayer of exosomes, this creates a synergistic "dual-barrier" protection system that markedly enhances therapeutic durability and clinical translatability. Poly(β-amino ester) (PAE) hydrogels-fabricated as biocompatible, three-dimensional scaffolds-retain the favorable properties of conventional hydrogels while additionally enabling sustained, controlled release, scalable manufacturing, and intrinsic neuroregenerative potential. In preclinical studies using a murine model of diabetic ocular surface disease, topical application of PAE hydrogel loaded with tRF-targeting ASO-engineered mesenchymal stem cell-derived exosomes (tRF-ASO-Exo) significantly attenuated ocular surface inflammation, promoted structural recovery of the corneal and conjunctival epithelium, and preserved corneal epithelial viability.

This study aims to evaluate a novel, non-invasive, topical hydrogel-based delivery system for tRF-ASO-loaded mesenchymal stem cell-derived exosomes (MSC-Exos) in patients with DOSD. The primary objective is to assess structural and functional ocular surface restoration using multimodal imaging and clinical metrics: anterior segment optical coherence tomography (AS-OCT), in vivo confocal microscopy (IVCM), slit-lamp-guided corneal fluorescein staining, and quantitative corneal sensitivity testing. Symptom improvement will be evaluated using the validated Ocular Surface Disease Index (OSDI). Secondary endpoints include tear secretion volume (Schirmer test), tear film breakup time (TBUT), ocular redness grading, tear meniscus height (via AS-OCT), and best-corrected visual acuity (BCVA).

A total of 30 participants will be enrolled and randomized into three intervention groups. Following a 14-day placebo run-in period-during which all subjects receive bilateral placebo eye drops (one drop per eye, twice daily, approximately 12 hours apart)-participants will receive active treatment for 84 days: Group 1 (Exo) receives 10 μg/drop of unmodified MSC-Exos; Group 2 (tRF-ASO-Exo) receives 10 μg/drop of MSC-Exos formulated in PAE hydrogel; and Group 3 (tRF-ASO-Exo-PAE) receives 10 μg/drop of tRF-ASO-engineered MSC-Exos delivered via PAE hydrogel-all administered twice daily. A 12-weeks follow-up will be conducted to monitor disease progression and durability of therapeutic effects.

Inclusion Criteria:

• 1. Patients with fasting blood glucose ≥ 7.0 mmol/L or 2-hour postprandial blood glucose ≥ 11.1 mmol/L.

  2. Those who clearly understand and voluntarily participate in this study, and sign the written informed consent form themselves, and are able and willing to follow the instructions to participate in all trial evaluations and visits.

  3. Male subjects and female subjects of childbearing age must agree to use medically approved contraceptive measures during the trial and for 90 days after the trial. For female subjects who have not reached menopause or have been menopausal for less than two years, the pregnancy test must be negative.

  4. A history of severe dry eye symptoms (including one or more of the following subjective symptoms: dryness, foreign body sensation, burning sensation, fatigue, discomfort, redness, sudden eye pain, photophobia, tearing, blurred vision, and decreased corneal sensation) in both eyes for at least 180 days before the screening visit (Visit 0).

  5. Currently (within 30 days before Visit 0) using artificial tears to relieve dry eye-related symptoms, and artificial tears must be discontinued 72 hours before Visit 0.

  6. At Visit 0, the Chinese Dry Eye Questionnaire score is > 7 points or the total score of the Ocular Surface Disease Index is > 13 points.

  7. At Visit 0 and Visit 1, the dryness score is > 40 points. 8. At Visit 0, the best corrected visual acuity of both eyes is ≥ 4.3 (5-meter reading on the international standard logarithmic visual acuity chart, 5-point recording method).

  9. At Visit 0 and Visit 1, the corneal fluorescein staining score of at least one area of at least one eye is ≥ 2 points.

  10. At Visit 0 and Visit 1, the conjunctival redness score of at least one eye is ≥ 1 point.

  11. At the screening visit and baseline visit (Visit 0 and Visit 1), at least one eye of the same subject meets the following criteria: a. The corneal lower zone fluorescein staining score is ≥ 0.5 points; b. The Schirmer's test without anesthesia is ≥ 1 and ≤ 10 mm/5 min.

Exclusion Criteria:

1. Any past or current malignancy in or around the eye.
2. Dry eye traced to scarring (radiation, alkali burn, Stevens-Johnson, cicatricial pemphigoid) or goblet-cell loss (vitamin-A deficiency).
3. Active ocular allergy now or expected during the study.
4. Ocular or systemic infection at screening/baseline-fever, herpetic keratitis, or on antibiotics.
5. Prior immunodeficiency, HIV, hep B/C, active hep A, organ or bone-marrow transplant.
6. Any serious chronic illness the PI thinks could mess with endpoints-severe heart/lung disease, uncontrolled hypertension or diabetes.
7. Blood donation or major blood loss within 8 weeks of screening.
8. Active ocular rosacea, periorbital acne, or pterygium.
9. Lid problems-lagophthalmos, entropion, ectropion, or abnormal blink.
10. Clinically relevant slit-lamp findings needing treatment (conjunctivitis, trichiasis, conjunctivochalasis) that could skew results.
11. Eye surgery or laser (including YAG, meibomian thermopulsation, IPL) within 6 months of screening, or any such plan during the trial.
12. Punctal plugs (non-dissolvable within 90 days; dissolvable within 180 days) or planned plug procedures during the study.
13. Systemic steroids, immunomodulators, oral doxy/tetracycline within 90 days, or on-and-off use planned.
14. Topical glaucoma meds within 90 days.
15. Cyclosporine-A or lifitegrast drops within 42 days.
16. Drugs well known to dry the eye-diuretics, antidepressants, decongestants, antispasmodics, antihistamines, etc.-within 30 days or irregular use expected.
17. Active blepharitis/MGD therapy (lid scrubs, meibomian massage, warm compresses, systemic antibiotics) within 30 days or sporadic use planned.
18. Topical steroid or mast-cell stabilizer on the eye/face within 2 weeks.
19. Contact-lens wear within 7 days or intent to keep wearing them during the study.