Preliminary study of the effect of FK506 nanospheric-suspension eye drops on rejection of penetrating keratoplasty

Sialylated IVIg promotes clinical improvements in a rabbit dry eye model by regulating inflammatory cytokines

Dry eye disease (DED) is caused by a loss of homeostasis of the tear film, which results in visual disturbance, ocular surface inflammation and damage, and neurosensory abnormalities. Although it is prevalent in 5-50% of the global population, there are limited clinical options for its treatment. This study explored the potential use of human intravenous immunoglobulin (IVIg) and its enriched fractions of sialylation, sialylated IVIg (sIVIg), as a treatment for DED. Fifteen female New Zealand white rabbits were topically instilled with 0.2% benzalkonium chloride (BAC) twice daily for five consecutive days to induce experimental dry eye. Saline, 0.4% IVIg, or 0.04% sIVIg eye drops were instilled twice daily for 20 consecutive days. Clinical evaluations, such as non-invasive tear break-up time (NIBUT) and corneal fluorescein staining (CFS), were conducted. mRNA levels of mucin 4, mucin 16, TNF-α, IL-1β, MMP9, IL-10, TGF-β, and CD209 in rabbit conjunctival tissues were examined using reverse transcription polymerase chain reaction (RT-PCR) or quantitative RT-PCR (qRT-PCR). The relationships between CD209 family members in rabbits and various mammalian species were analyzed using a phylogenetic tree. IVIg or sIVIg treatment resulted in clinical improvements in the rabbit DED model. The inflammatory cytokines, TNF-α and IL-1β, were increased and mucin 4 and mucin 16, cell surface-associated mucins, were decreased in BAC-induced dry eye. Following IVIg or sIVIg treatment, inflammatory cytokines decreased, whereas the anti-inflammatory cytokine, IL-10, increased substantially. Moreover, a 10-fold lower sIVIg treatment dose resulted in prolonged IL-10 production, representing a significantly improved DED compared to IVIg. Furthermore, the expression of rabbit CD209 mRNA in the rabbit conjunctiva and its close relationship with primate homologs suggest that it may interact with IVIg or sIVIg to promote IL-10 expression, as previously described in humans. At a lower dosage, sIVIg showed a more efficient improvement in DED, making it a promising new candidate medication for DED.

Current approaches for the regeneration and reconstruction of ocular surface in dry eye

Significant research revealed the preocular tear film composition and regulations that remain vital for maintaining Ocular surface functional integrity. Inflammation triggered by many factors is the hallmark of Ocular surface disorders or dry eyes syndrome (DES). The tear deficiencies may lead to ocular surface desiccation, corneal ulceration and/or perforation, higher rates of infectious disease, and the risk of severe visual impairment and blindness. Clinical management remains largely supportive, palliative, and frequent, lifelong use of different lubricating agents. However, few advancements such as punctal plugs, non-steroidal anti-inflammatory drugs, and salivary gland autografts are of limited use. Cell-based therapies, tissue engineering, and regenerative medicine, have recently evolved as long-term cures for many diseases, including ophthalmic diseases. The present article focuses on the different regenerative medicine and reconstruction/bioengineered lacrimal gland formation strategies reported so far, along with their limiting factors and feasibility as an effective cure in future.

Polymer nanotherapeutics to correct autoimmunity

The immune system maintains homeostasis and protects the body from pathogens, mutated cells, and other harmful substances. When immune homeostasis is disrupted, excessive autoimmunity will lead to diseases. To inhibit the unexpected immune responses and reduce the impact of treatment on immunoprotective functions, polymer nanotherapeutics, such as nanomedicines, nanovaccines, and nanodecoys, were developed as part of an advanced strategy for precise immunomodulation. Nanomedicines transport cytotoxic drugs to target sites to reduce the occurrence of side effects and increase the stability and bioactivity of various immunomodulating agents, especially nucleic acids and cytokines. In addition, polymer nanomaterials carrying autoantigens used as nanovaccines can induce antigen-specific immune tolerance without interfering with protective immune responses. The precise immunomodulatory function of nanovaccines has broad prospects for the treatment of immune related-diseases. Besides, nanodecoys, which are designed to protect the body from various pathogenic substances by intravenous administration, are a simple and relatively noninvasive treatment. Herein, we have discussed and predicted the application of polymer nanotherapeutics in the correction of autoimmunity, including treating autoimmune diseases, controlling hypersensitivity, and avoiding transplant rejection.

Formulation and development of tacrolimus-gellan gum nanoformulation for treatment of dry eye disease

The present study aimed at the development and evaluation of tacrolimus gellan gum nanoparticles (TGNPs) for the effective management of dry eye disease (DED) following topical application. TGNPs were developed by ionotropic gelation between gellan gum and aluminum chloride. Developed TGNPs were nanosized (274.46 ± 8.90 nm) with high % encapsulation efficiency (74.2 ± 2.4%) and loading capacity (36.14 ± 1.7%). The nanosize and spherical morphology of TGNPs was confirmed by transmission electron microscopy (TEM) and atomic force microscopy (AFM). Fourier transform infrared spectroscopy (FTIR) revealed no interaction between drug and GG. Differential scanning calorimetry (DSC) and X-ray diffraction (XRD) confirms the conversion of crystalline tacrolimus to amorphous post encapsulation in the nanoparticle. TGNPs showed prolonged drug release throughout 12 h and higher pre-corneal retention compared to tacrolimus solution. HET-CAM studies, histopathological evaluation, and Draize test confirmed the safety of the formulation for ocular use. Further, the pharmacodynamic studies using experimental DED in rabbits showed that TGNPs are effective in treating symptoms of DED. In conclusion, topical delivery of TGNPs could hold potential for efficient management of DED.

Formulation development, optimization, and in vitro assessment of thermoresponsive ophthalmic pluronic F127-chitosan in situ tacrolimus gel

To overcome problems associated with topical delivery of tacrolimus (TCS), a thermoresponsive in situ gel system containing pluronic F127 (PL), and chitosan (CS) was developed, to enhance the precorneal retention, and to sustain the release of the drug. The PL-CS in situ gel was optimized using a 2-factor-3-level central composite experimental design by selecting the concentration of PL and CS as independent variables while gelation time, gelation temperature, and spreadability as dependent variables. The optimized formulation was developed using 22.5 g PL and 0.3 g CS, gels at 33.6 °C, in 22.93 s, and showed the spreadability of 6.2 cm. In vitro studies conducted for the optimized gel revealed the sustained release of TCS (81.73% in 4 h) and improved corneal permeation (74.13% in 4 h), compared with TCS solution. The mechanism of release of TCS followed the Higuchi model with Fickian diffusion transport. Further, histopathology and HET-CAM studies revealed that the developed gel was non-irritating and safe for ocular administration.

Surface functionalized mesoporous silica nanoparticles for intravitreal application of tacrolimus

Tacrolimus (TAC), a potent immunosuppressive macrolide, has been investigated for ocular diseases due to promising results in the treatment of anterior and posterior segments eye diseases. Mesoporous and functionalized silica nanoparticles show potential as TAC delivery platforms owing to their interesting characteristic as large surface area, uniform pore size distribution, high pore volume, and excellent biocompatibility. The purpose of this study was to incorporate TAC in functionalized silica nanoparticles with 3-aminopropyltriethoxysilane (MSNAPTES) and investigate the safety and biocompatibility of the systems. The MSNAPTES and MSNAPTES TAC nanoparticles were characterized. The in vitro cytotoxicity of MSNAPTES and MSNAPTES load with TAC (MSNAPTES-TAC) in retinal pigment epithelial cells (ARPE-19) was determined, chorioallantoic membrane (CAM) assay model was used to investigate the in vivo biocompatibility, and safety of intravitreal injection was evaluated using clinical examination (assessment of intraocular pressure and indirect fundus ophthalmoscopy), electroretinographic (ERG) and histologic studies in rats' eyes. The elemental analysis (CHN), thermogravimetric (TGA), photon correlation spectroscopy and Fourier transform infrared (FTIR) analysis confirmed the presence of functionalized agent and TAC in the MSNAPTES nanoparticles. TAC loading was estimated at 7% for the MSNAPTES TAC nanoparticles. MSNAPTES and MSNAPTES TAC did not present in vitro cytotoxicity. The drug delivery systems showed good biocompatibility on CAM. No retinal abnormalities, vitreous hemorrhage, neovascularization, retinal detachment, and optic nerve atrophy were observed during the in vivo study. Follow-up ERGs showed no changes in the function of the retina cells after 15 days of intravitreal injection, and histopathologic observations support these findings. In conclusion, MSNAPTES TAC was successfully synthesized, and physicochemical analyses confirmed the presence of TAC in the nanoparticles. In vitro and in vivo studies indicated that MSNAPTES TAC was safe to intravitreal administration. Taking into account the enormous potential of MSNAPTES to carry TAC, this platform could be a promising strategy for TAC ocular drug delivery in the treatment of eye diseases.

Development and effects of tacrolimus-loaded nanoparticles on the inhibition of corneal allograft rejection

Tacrolimus has been widely applied to prevent organ rejection after transplantation. However, the conventional pharmaceutical formulation of tacrolimus limits its applications in ocular therapy due to its hydrophobicity and low corneal penetrability. We optimized tacrolimus-loaded methoxy poly (ethylene glycol-block-poly (d, l)-lactic-co-glycolic acid) nanoparticles (TAC-NPs) by simple and effective nanotechnology as a drug delivery system for corneal graft rejection to overcome these drawbacks. The prepared TAC-NPs were 82.9 ± 1.3 nm in size, and the drug loading and encapsulation efficiency were 8.01 ± 0.23% and 80.10 ± 2.33%. Furthermore, New Zealand rabbits were used to analyze the single-dose pharmacokinetics of the TAC-NPs using high-performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS). In rats with allogenic penetrating keratoplasty, the administration of TAC-NPs dispersion drops improved the TAC concentrations in the aqueous humor and cornea, consistent with a significantly higher effective inhibition of IL-2, IL-17, and VEGF expression compared with conventional 0.1% tacrolimus drops. Meanwhile, we also compared two different topical administration methods (including eye drop and subconjunctival injection) of TAC-NPs to maximize the sustained release characteristic of NPs. In summary, the small-sized TAC-NPs enhanced transcorneal permeation and absorption of TAC and more effectively inhibited corneal allograft rejection, which indicated that biodegradable polymeric nanomaterials-based drug delivery system had great potential for improving the clinical therapy efficacy of hydrophobic drugs.

Topical nanodelivery system of lutein for the prevention of selenite-induced cataract

Cataracts are responsible for half of the world blindness, surgery being the only viable treatment. Lutein, a naturally occurring carotenoid in the eye, has the potential to reduce cataract progression by protecting the eye from photo-oxidative stress. To restore the eye's natural line of defense against photo-oxidative stress, a formulation was developed using zein and poly(lactic-co-glycolic acid) nanoparticles (NPs) embedded in an optimized bioadhesive thermosensitive gel for the delivery of lutein via topical application. Cataracts were induced in Crl:WI rats via selenite injection at 13 days post-partum, followed by 7 days of treatment with free lutein or lutein-loaded NPs administered orally or topically. Cataract severity was significantly reduced in rats treated with topical applications of lutein-loaded NPs compared to the positive control, while no significant differences were observed in rats treated with other lutein formulations including oral and topically applied free lutein.

Proniosomes derived niosomes: recent advancements in drug delivery and targeting

Vesicular drug delivery systems have gained wide attention in the field of nanotechnology. Among them proniosomes become the superior over other vesicular carriers. Proniosomes are dry formulations of water soluble nonionic surfactant coated carrier system which immediately forms niosomes upon hydration. They have the capability to overcome the instability problems associated with niosomes and liposomes and have the potential to improve solubility, bioavailability, and absorption of various drugs. Furthermore, they offer versatile drug delivery concept for enormous number of hydrophilic and hydrophobic drugs. They have the potential to deliver drugs effectively through different routes at specific site of action to achieve controlled release action and reduce toxic effects associated with drugs. This review discusses the general preparation techniques of proniosomes and mainly focus on the applications of proniosomes in drug delivery and targeting. Moreover, this review demonstrates critical appraisal of the literature for proniosomes. Additionally, this review extensively explains the potential of proniosomes in delivering drugs via different routes, such as oral, parenteral, dermal and transdermal, ocular, oral mucosal, vaginal, pulmonary, and intranasal. Finally, the comparison of proniosomes with niosomes manifests the clear distinction between them. Moreover, proniosomes need to be explored for proteins and peptide delivery and in the field of nutraceuticals and develop pilot plant scale up studies to investigate them in industrial set up.

Tacrolimus downregulates inflammation by regulating pro‑/anti‑inflammatory responses in LPS‑induced keratitis

Lipopolysaccharide (LPS)-induced keratitis is a progressive infectious ocular disease in which innate inflammatory responses often cause clinical tissue damage and vision loss. The present study aimed to investigate the effects of tacrolimus, an effective immunomodulator, on LPS-induced innate immune responses. The effects of tacrolimus on the apoptotic rate and viability of human corneal epithelial cells (HCECs), polymorphonuclear neutrophils (PMNs) and monocytes (THP-1 cells) were examined using flow cytometry and MTT assays. Subsequently, the role of tacrolimus on LPS-induced inflammation in HCECs, PMNs and THP-1 cells was evaluated by detecting the expression levels of pro-inflammatory cytokines, including interleukin (IL)-1β, IL-6 and matrix metallopeptidase 9; anti-inflammatory cytokines, including IL-10 and transforming growth factor-β; and proangiogenic factors, including vascular endothelial growth factor and tumor necrosis factor-α using quantitative polymerase chain reaction. The results demonstrated that tacrolimus had good biocompatibility with HCECs, while promoting apoptosis and decreasing the viability of PMNs and THP-1 cells. Furthermore, tacrolimus effectively reduced the expression levels of pro-inflammatory cytokines and increased anti-inflammatory cytokines in LPS-induced keratitis in vitro. Notably, tacrolimus decreased the levels of proangiogenic factors, which are highly increased following LPS stimulation. Conclusively, tacrolimus appears to be a safe and effective treatment to suppress neutrophil and monocyte activity, modulate the balance of pro-/anti-inflammatory cytokines, and reduce the inflammatory response and angiogenic activity in LPS-induced bacterial keratitis.

Topical tacrolimus in anterior segment inflammatory disorders

Immune mediated inflammatory anterior segment diseases are variable and their management requires intense immunosuppression. Treatment with topical steroids is associated with serious ocular side effects. In order to overcome the potentially blinding complications of topical steroids, immunomodulatory drugs are being used more frequently. Tacrolimus is a calcineurin inhibitor that induces suppression of T lymphocytes activity and reduction of ocular inflammation. Tacrolimus was recently investigated for application in various anterior segment inflammatory disorders. In this review, we will discuss the therapeutic application of topical tacrolimus as a steroid-sparing agent in treating T cell mediated anterior segment inflammation.

Hyaluronic acid-coated niosomes facilitate tacrolimus ocular delivery: Mucoadhesion, precorneal retention, aqueous humor pharmacokinetics, and transcorneal permeability

Tacrolimus (FK506) was used to prevent corneal allograft rejection in patients who were resistant to steroids and cyclosporine. However, the formulation for FK506 ocular delivery remained a challenge due to the drug's high hydrophobicity, high molecular weight, and eye's physiological and anatomical constraints. The aim of this project is to develop an ocular delivery system for FK506 based on a combined strategy of niosomes and mucoadhesive hyaluronic acid (HA), i.e., FK506HA-coated niosomes, which exploits virtues of both niosomes and HA to synergistically improve ophthalmic bioavailability. The FK506HA-coated niosomes were characterized with particle size, zeta potential, and rheology behavior. Mucoadhesion of FK506HA-coated niosomes to mucin was investigated through surface plasmon resonance in comparison with non-coated niosomes and HA solution. The results showed that niosomes possessed adhesion to mucin, and HA coating enhanced the adhesion. The in vivo precorneal retention was evaluated in rabbit, and the results showed that HA-coated niosomes prolonged the residence of FK506 significantly in comparison with non-coated niosomes or suspension. Aqueous humor pharmacokinetics test showed that area under curve of HA-coated niosomes was 2.3-fold and 1.2-fold as that of suspension and non-coated niosomes, respectively. Moreover, the synergetic corneal permeability enhancement of the hybrid delivery system on FK506 was visualized and confirmed by confocal laser scanning microscope. Overall, the results indicated that the hybrid system facilitated FK506 ocular delivery on mucoadhesion, precorneal retention, aqueous humor pharmacokinetics and transcorneal permeability. Therefore, HA-coated niosomes may be a promising approach for ocular targeting delivery of FK506.

Comparative study of tacrolimus and bevacizumab on corneal neovascularization in rabbits

PURPOSE

To compare the antiangiogenic effects of tacrolimus and bevacizumab on corneal neovascularization (CNV) in rabbits.

METHODS

Neovascularization was induced in 32 eyes of 16 rabbits by placing a suture in the corneal stroma. Seven days after suture placement, all rabbits were divided into 4 groups and were treated subconjunctivally with bevacizumab (AVA_sub) 0.05 mL (5 mg/0.05 mL), tacrolimus (TAC_sub) 0.05 mL (0.25 mg/0.05 mL), balanced salt solution (0.05 mL was subconjunctivally injected in 1 eye of each rabbit and applied by eye drops in the other eyes, control group), and tacrolimus eye drops (TAC_drop) (5 mg/5 mL applied 4 times daily). Digital photographs were obtained and surface area of CNV was measured 7 days after subconjunctival injections. Corneal specimens were analyzed histopathologically and were used to measure the concentration of vascular endothelial growth factor (VEGF), tumor necrosis factor alpha (TNF-α), interferon gamma (IFN-γ), interleukin-1 beta (IL-1β), and monocyte chemoattractant protein 1 mRNA by reverse transcription polymerase chain reaction.

RESULTS

In digital photographs, the neovascularized area was decreased in all treatment groups (AVA_sub, 0.58; TAC_sub, 0.60; TAC_drop, 0.68) compared with the control group (balanced salt solution, 0.81). Histological examination showed markedly regressed new vessels in treatment groups, and immunohistochemical staining revealed weakly stained anti-VEGF and anti-F4/80 antibodies in treatment groups. In semiquantitative reverse transcription polymerase chain reaction, concentration of VEGF (AVA_sub, 0.24; TAC_drop, 0.18), TNF-α (AVA_sub, 0.19; TAC_sub, 0.24; TAC_drop 0.15), and IL-1β (AVA_sub, 0.19; TAC_sub, 0.33; TAC_drop, 0.18) mRNA were significantly lower in treatment groups than in the control group (VEGF, 0.47; TNF-α, 0.44; IL-1β, 0.87) (P < 0.05).

CONCLUSIONS

Topical and subconjunctival tacrolimus application may be useful in reducing CNV and have comparable effects to subconjunctival bevacizumab injection.

Tacrolimus (FK506) suppresses TREM-1 expression at an early but not at a late stage in a murine model of fungal keratitis

PURPOSE

To investigate the efficacy and mechanism of tacrolimus(FK506), which is a novel macrolide immunosuppressant, in inhibiting triggering receptor expressed on myeloid cells-1 (TREM-1) expression in a murine keratitis model induced by Aspergillus fumigatus.

METHOD

TREM-1 was detected in 11 fungus-infected human corneas by quantitative real-time PCR (qRT-PCR). RAW264.7 macrophages were divided into four groups, which received treatment with zymosan (100 µg/ml), zymosan (100 µg/ml) + mTREM-1/Fc protein (1 µg/ml), or zymosan (100 µg/ml) + FK506 (20 µM) or negative-control treatment. After this treatment, the expression of TREM-1, interleukin-1β (IL-1β) and tumor necrosis factor α (TNFα) was assayed using qRT-PCR and ELISA. The mouse model of fungal keratitis was created by intrastromal injection with Aspergillus fumigatus, and the mice were divided into 2 groups: group A received vehicle eye drops 4 times each day, and group B received 4 doses of FK506 eye drops each day. Corneal damage was evaluated by clinical scoring and histologic examination,and myeloperoxidase (MPO) protein levels were also detected by ELISA. The expression of TREM-1, IL-1β and TNFα was then determined at different time points using qRT-PCR and ELISA.

RESULTS

TREM-1 expression dramatically increased in the human corneas with fungal keratitis. In contrast, FK506 reduced the expression of TREM-1, IL-1β and TNFα in RAW264.7 macrophages stimulated with zymosan. In the mouse model, at day 1 post-infection, the corneal score of the FK506-treated group was lower than that of the control, and polymorphonuclear neutrophil (PMN) infiltration was diminished. TREM-1, IL-1β and TNFα expression was significantly reduced at the same time point. However, the statistically significant differences in cytokine expression, clinical scores and infiltration disappeared at 5 days post-infection.

CONCLUSIONS

FK506 may inhibit the inflammation induced by fungi and alleviate the severity of corneal damage at an early stage of fungal keratitis by downregulating TREM-1 expression.

Evaluation of corneal graft survival in mice model

AIM

To investigate the characteristics and criterion of graft rejection in mice model.

METHODS

C57BL/6 or BALB/c mice corneal grafts were grafted onto BALB/c hosts. Each group was divided into two subgroups according to the corneal opacity scores 12d after transplantation. The characteristics of opacity and neovascularization were observed. Mice of the 12(th), 50(th) day after transplantation, the grafts biopsy of mice in allogeneic group 1, which opacity score exceed 3, were prepared for histological observation and those restore transparent were endothelial stained.

RESULTS

There was no difference of corneal opacity score on the 7(th) and 12(th) day after operation; the histological results had no disparity between syngeneic group and allogeneic group. On the 12(th) day after surgery, the turbidity curve was apparent in grafts with opacity score < 2. Mononuclear cells were shown in grafts with opacity score reached 3 in allogeneic group 1. Different rejection performance was observed in tissue sections on the 50(th) day after surgery.

CONCLUSION

Grafts, opacity score exceeds 3 from the 7(th) to the 12(th) day after operation could not be judged as a rejection. We should pay more attention to the variation of grafts opacity since 12d after corneal transplantation.

Nanoparticles in the ocular drug delivery

Ocular drug transport barriers pose a challenge for drug delivery comprising the ocular surface epithelium, the tear film and internal barriers of the blood-aqueous and blood-retina barriers. Ocular drug delivery efficiency depends on the barriers and the clearance from the choroidal, conjunctival vessels and lymphatic. Traditional drug administration reduces the clinical efficacy especially for poor water soluble molecules and for the posterior segment of the eye. Nanoparticles (NPs) have been designed to overcome the barriers, increase the drug penetration at the target site and prolong the drug levels by few internals of drug administrations in lower doses without any toxicity compared to the conventional eye drops. With the aid of high specificity and multifunctionality, DNA NPs can be resulted in higher transfection efficiency for gene therapy. NPs could target at cornea, retina and choroid by surficial applications and intravitreal injection. This review is concerned with recent findings and applications of NPs drug delivery systems for the treatment of different eye diseases.

Comparison of tacrolimus, fluorometholone, and saline in mild-to-moderate contact lens-induced papillary conjunctivitis

INTRODUCTION

The purpose of this study was to compare the efficacy of tacrolimus, fluorometholone, and saline in the treatment of mild to moderate contact lens-induced papillary conjunctivitis (CLPC).

METHODS

This was a double-masked, randomized pilot study. A total of 18 soft contact lens users (n = 36 eyes) with mild to moderate papillary conjunctivitis were enrolled. Subjects were randomly assigned into three groups to receive tacrolimus 0.05%, fluorometholone 0.1%, or saline (sodium chloride 0.9%). Drugs were prescribed at the baseline visit (visit 1) and instilled twice daily for 4 weeks. Follow-up visits were taken at week 1 (visit 2), week 2 (visit 3), week 4 (visit 4, drug usage suspended at this visit), and week 6 (visit 5, 2 weeks after interrupting eye drops). Contact lens use was discontinued during the 6 weeks of the study, and variables assessed were symptoms and signs, tear film status, and intraocular pressures. Conjunctival impression cytology was performed at baseline and visit 5 to assess ocular surface status.

RESULTS

Mean roughness and redness scores decreased significantly from visit 1 to visit 5, but the variation tendency was comparable in all groups (P = 0.180 and 0.889, respectively). Subjective symptom parameters were improved in all CLPC patients at visit 5, and there was no remarkable difference in symptom reduction in three groups. The mean Schirmer value and mean break-up time (BUT) did not change significantly in the three groups during the study. Ocular surface findings by impression cytology improved significantly after three treatments. Intraocular pressure fluctuation from baseline to 6-week follow-up was not statistically significant in all subjects. No adverse treatment-related event was observed in any study group.

CONCLUSIONS

Tacrolimus 0.05% may be a safe and effective treatment for mild to moderate CLPC and is comparable with fluorometholone 0.1% in efficacy. Contact lens cessation accompanied with saline may also be effective in treating mild to moderate CLPC.