Corneal Wound Healing in the Presence of Antifibrotic Antibody Targeting Collagen Fibrillogenesis: A Pilot Study.

Highly organized collagen fibrils interlacing with proteoglycans form the crucial architecture of the cornea and facilitate its transparency. Corneal scarring from accidental injury, surgery, or infection alters this highly organized tissue, causing severe consequences, including blindness. There are no pharmacological or surgical methods to effectively and safely treat excessive corneal scarring. Thus, we tested the anticorneal scarring utility of a rationally designed anticollagen antibody (ACA) whose antifibrotic effects have already been demonstrated in nonocular models. Utilizing a rabbit model with an incisional corneal wound, we analyzed ACA's effects on forming collagen and proteoglycan-rich extracellular matrices in scar neotissue. We used microscopic and spectroscopic techniques to quantify these components and measure crucial parameters characterizing the structure and organization of collagen fibrils. Moreover, we analyzed the spatial distribution of collagen and proteoglycans in normal and healing corneas. Our study demonstrated significant changes in the quality and quantity of the analyzed molecules synthesized in scar neotissue. It showed that these changes extend beyond incision margins. It also showed ACA's positive impact on some crucial parameters defining proper cornea structure. This pilot study provides a stepping stone for future tests of therapeutic approaches that target corneal extracellular scar matrix assembly.

Fibroblasts from recurrent fibrotic overgrowths reveal high rate of proliferation in vitro - findings from the study of hereditary and idiopathic gingival fibromatosis.

PURPOSE: Investigate the content of fibrotic fibrils in gingival tissue and the proliferation of fibroblasts collected from recurrent and non-recurrent hereditary gingival fibromatosis (HGF) and idiopathic gingival fibromatosis (IGF). METHODS: Gingival biopsies were collected from HGF (n = 3) and IGF (n = 3) donors with recurrent and non-recurrent gingival overgrowths and from a control group (Ctrl, n = 3). Hematoxylin staining was performed to evaluate the histomorphology of gingival tissue. Heidenhain's AZAN trichrome staining served for visualization of fibrotic fibrils in gingiva. Quantitative analysis of the content of fibrotic fibrils in gingival tissue was performed using a polarized light microscope. Proliferation was evaluated at 24 h, 48 h, and 72 h in fibroblast cultures using a cell proliferation ELISA assay based on 5-bromo-2'-deoxyuridine (BrdU). RESULTS: Numerous blood vessels and fibroblasts were observed in recurrent overgrowths, whereas moderate blood vessels and moderate to scanty fibroblasts were detected in non-recurrent overgrowths. Heidenhain's staining revealed numerous collagen fibers in both recurrent and non-recurrent overgrowths. Quantitative analysis in a polarizing microscope showed significant accumulation of fibrotic fibrils exclusively in the overgrowths with the recurrence. In all time-points, increased proliferation of cells from all recurrent overgrowths was observed, but not from overgrowths which do not reoccur. CONCLUSIONS: The study revealed that recurrent gingival overgrowths consist of highly fibrotic and dense connective tissue with numerous blood vessels and abundant fibroblasts. We also demonstrated that unlike fibroblasts derived from overgrowths, which did not present recurrence, fibroblasts derived from highly fibrotic and recurrent overgrowths maintain high rate of proliferation in vitro.

TIMP-1 association with collagen type I overproduction in hereditary gingival fibromatosis.

OBJECTIVES: To investigate the processes associated with the excessive production of collagen I in hereditary gingival fibromatosis (HGF). MATERIALS AND METHODS: Three HGF subjects and five controls were enrolled in the study. Histomorphological and immunohistological analyses were performed on gingival tissues. The expression of heat-shock protein 47 (HSP47), collagen I, transforming growth factor-ß1 (TGF-ß1), connective tissue growth factor (CTGF), matrix metalloproteinase-1 (MMP-1) and tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) by gingival fibroblasts isolated from HGF and controls was analysed using qRT-PCR, Western blotting and ELISA. RESULTS: Considerable accumulation of fibrotic fibrils and increased synthesis of HSP47 were noted in HGF gingival tissues. The synthesis of collagen I, HSP47, TGF-ß1, CTGF and TIMP-1 was significantly elevated in HGF gingival fibroblasts compared with controls, while the production of MMP-1 was decreased. CONCLUSIONS: We report that fibrosis in HGF gingival tissues is associated with increased synthesis of HSP47. This finding was confirmed by an in vitro study, where excessive production of collagen I was associated with increased synthesis of HSP47, TGF-ß1 and CTGF by HGF gingival fibroblasts. Moreover, the shift in the TIMP-1/MMP-1 ratio identifies increased synthesis of TIMP-1 as one of the processes associated with collagen I overproduction in HGF fibroblasts.

P15 peptide stimulates chondrogenic commitment and endochondral ossification.

PURPOSE: The synthetic 15 amino acid biomimetic peptide sequence (P15) derived from a region of the alpha (α)-1 chain of collagen I, has been shown to promote α2 integrin activation and enhance intramembranous ossification. In this study, we ask if the P15 peptide also enhances bone formation through endochondral ossification, and determine if direct binding of α2 integrin with P15 mediates integrin activation. METHODS: Mesenchymal cells (C3H10T1/2) were cultured in chondrogenic media and the expression of chondrogenic markers and integrin activation was determined by Western blot and fluorescent immunohistochemistry. A biosensor assay was used to determine if binding occurred between P15 and α2 ß1 integrin. Finally, an in vivo model of endochondral ossification was used to determine the effect of P15 on bone formation. RESULTS: In the presence of P15, chondrogenesis and activation of α5 integrin were enhanced, as observed by both Western blot analysis and immunoflourescent staining. A biosensor assay investigating the specificity of the interaction between P15 with α2ß1 integrin determined direct binding does not occur. When P15 was added to Matrigel implanted in a murine endochondral ossification model, in the presence of bone morphogenic protein-2 (BMP-2), a significant increase in chondrocyte differentiation and mineralization was observed. CONCLUSION: P15 does not directly activate integrins by binding, but does upregulate integrin signaling to enhance differentiation of both osteoblasts and chondrocytes to increase both intramembranous and endochondral bone formation.

Mechanisms of aberrant organization of growth plates in conditional transgenic mouse model of spondyloepiphyseal dysplasia associated with the R992C substitution in collagen II.

Mutations in collagen II, a main structural protein of cartilage, are associated with various forms of spondyloepiphyseal dysplasia (SED), whose main features include aberrations of linear growth. Here, we analyzed the pathomechanisms responsible for growth alterations in transgenic mice with conditional expression of the R992C collagen II mutation. Specifically, we studied the alterations of the growth plates of mutant mice in which chondrocytes lacked their typical columnar arrangement. Our studies demonstrated that chondrocytes expressing the thermolabile R992C mutant collagen II molecules endured endoplasmic reticulum stress, had atypical polarization, and had reduced proliferation. Moreover, we demonstrated aberrant organization and morphology of primary cilia. Analyses of the extracellular collagenous deposits in mice expressing the R992C mutant collagen II molecules indicated their poor formation and distribution. By contrast, transgenic mice expressing wild-type collagen II and mice in which the expression of the transgene encoding the R992C collagen II was switched off were characterized by normal growth, and the morphology of their growth plates was correct. Our study with the use of a conditional mouse SED model not only indicates a direct relation between the observed aberration of skeletal tissues and the presence of mutant collagen II, but also identifies cellular and matrix elements of the pathomechanism of SED.

Developmental upregulation of an alternative form of pcp2 with reduced GDI activity.

The pcp2/L7 gene is characterized by its very cell type-specific expression restricted to cerebellar Purkinje cells and retinal bipolar neurons. Although remarkable progress as to the biochemical properties of the encoded protein has been made, knowledge on its physiological functions remains sparse. While characterizing a pcp2-driven transgenic strain, we observed the presence of a longer, so far unknown, pcp2 transcript. Different from another recently discovered splice variant, ret-pcp2, expression of this novel transcript is observed in bipolar as well as cerebellar Purkinje cells of mid-postnatal mice. The protein encoded by our novel variant appears to be less efficient in binding to Gα subunits compared to the original L7/pcp2 protein and it is also less inhibitory with respect to GTPγ binding. Its expression in the eye appears to be independent from eye opening in postnatal mice.

Testing the anti-fibrotic potential of the single-chain Fv antibody against the α2 C-terminal telopeptide of collagen I.

Abstract This study focuses on the single-chain fragment variable (scFv) variant of the original IgA-type antibody, recognizing the α2 C-terminal telopeptide (α2Ct) of human collagen I, designed to inhibit post-traumatic localized fibrosis via blocking the formation of collagen-rich deposits. We have demonstrated that the scFv construct expressed in yeast cells was able to fold into an immunoglobulin-like conformation, but it was prone to forming soluble aggregates. Functional assays, however, indicate that the scFv construct specifically binds to the α2Ct epitope and inhibits collagen fibril formation both in vitro and in a cell culture model representing tissues that undergo post-traumatic fibrosis. Thus, the presented study demonstrates the potential of the scFv variant to serve as an inhibitor of the excessive formation of collagen-rich fibrotic deposits, and it reveals certain limitations associated with the current stage of development of this antibody construct.

Kuskokwim syndrome, a recessive congenital contracture disorder, extends the phenotype of FKBP10 mutations.

Recessive mutations in FKBP10 at 17q21.2, encoding FKBP65, cause both osteogenesis imperfecta (OI) and Bruck syndrome (OI plus congenital contractures). Contractures are a variable manifestation of null/missense FKBP10 mutations. Kuskokwim syndrome (KS) is an autosomal recessive congenital contracture disorder found among Yup'ik Eskimos. Linkage mapping of KS to chromosome 17q21, together with contractures as a feature of FKBP10 mutations, made FKBP10 a candidate gene. We identified a homozygous three-nucleotide deletion in FKBP10 (c.877_879delTAC) in multiple Kuskokwim pedigrees; 3% of regional controls are carriers. The mutation deletes the highly conserved p.Tyr293 residue in FKBP65's third peptidyl-prolyl cis-trans isomerase domain. FKBP10 transcripts are normal, but mutant FKBP65 is destabilized to a residual 5%. Collagen synthesized by KS fibroblasts has substantially decreased hydroxylation of the telopeptide lysine crucial for collagen cross-linking, with 2%-10% hydroxylation in probands versus 60% in controls. Matrix deposited by KS fibroblasts has marked reduction in maturely cross-linked collagen. KS collagen is disorganized in matrix, and fibrils formed in vitro had subtle loosening of monomer packing. Our results imply that FKBP10 mutations affect collagen indirectly, by ablating FKBP65 support for collagen telopeptide hydroxylation by lysyl hydroxylase 2, thus decreasing collagen cross-links in tendon and bone matrix. FKBP10 mutations may also underlie other arthrogryposis syndromes.

Engineering and characterization of the chimeric antibody that targets the C-terminal telopeptide of the α2 chain of human collagen I: a next step in the quest to reduce localized fibrosis.

Inhibition of the extracellular process of collagen fibril formation represents a new approach to limiting posttraumatic or postsurgical localized fibrosis. It has been demonstrated that employing a monoclonal antibody that targets the C-terminal telopeptide of the α2 chain of collagen I blocks critical collagen I-collagen I interaction, thereby reducing the amount of collagen deposits in vitro and in animal models. Here, we developed a chimeric variant of a prototypic inhibitory antibody of mouse origin. The structure of this novel antibody was analyzed by biochemical and biophysical methods. Moreover, detailed biochemical and biological studies were employed to test its antigen-binding characteristics. The ability of the chimeric variant to block formation of collagen fibrils was tested in vitro and in high-density cultures representing fibrotic processes occurring in the skin, tendon, joint capsule, and gingiva. The potential toxicity of the novel chimeric antibody was analyzed through its impact on the viability and proliferation of various cells and by testing its tissue cross-reactivity in sets of arrays of human and mouse tissues. Results of the presented studies indicate that engineered antibody-based blocker of localized fibrosis is characterized by the following: (1) a correct IgG-like structure, (2) high affinity and high specificity for a defined epitope, (3) a great potential to limit the accumulation of collagen-rich deposits, and (4) a lack of cytotoxicity and nonspecific tissue reactivity. Together, the presented study shows the great potential of the novel chimeric antibody to limit localized fibrosis, thereby setting ground for critical preclinical tests in a relevant animal model.

Scar formation in the presence of mitomycin C and the anti-fibrotic antibody in a rabbit model of glaucoma microsurgery: A pilot study.

Purpose: This study aimed to evaluate the utility of a rationally engineered antibody that directly blocks collagen fibrillogenesis to reduce scar tissue formation associated with subconjunctival glaucoma surgery. Material and methods: Fourteen eyes of 7 adult rabbits underwent glaucoma filtering surgery using XEN 45 Gel Stent. The rabbits' eyes were divided randomly into three treatment groups: (i) treated with the antibody, (ii) treated with mitomycin C, and (iii) treated with the antibody and mitomycin C. Following surgeries, the intraocular pressure and bleb appearance were evaluated in vivo. The rabbits were sacrificed 8 weeks after the surgery, and their eyes were harvested and processed for tissue analysis. Subsequently, tissue samples were analyzed microscopically for fibrotic tissue and cellular markers of inflammation. Moreover, the collagen-rich fibrotic tissue formed around the stents was analyzed using quantitative histology and infrared spectroscopy. The outcomes of this study were analyzed using the ANOVA test. Results: This study demonstrated no significant differences in intraocular pressure, bleb appearance, or presence of complications such as bleb leak among the treatment groups. In contrast, we observed significant differences among the subpopulations of collagen fibrils formed within scar neo-tissue. Based on the spectroscopic analyses, we determined that the relative content of mature collagen cross-links in the antibody-treated group was significantly reduced compared to other groups. Conclusions: Direct blocking of collagen fibrillogenesis with the anti-collagen antibody offers potentially beneficial effects that may reduce the negative impact of the subconjunctival scarring associated with glaucoma filtering surgery.

Profibrotic behavior of fibroblasts derived from patients that develop posttraumatic shoulder stiffness.

Background and Aims: Arthrofibrosis is a severe scarring condition characterized by joint stiffness and pain. Fundamental to developing arthrofibrotic scars is the accelerated production of procollagen I, a precursor of collagen I molecules that form fibrotic deposits in affected joints. The procollagen I production mechanism comprises numerous elements, including enzymes, protein chaperones, and growth factors. This study aimed to elucidate the differences in the production of vital elements of this mechanism in surgical patients who developed significant posttraumatic arthrofibrosis and those who did not. Methods: We studied a group of patients who underwent shoulder arthroscopic repair of the rotator cuff. Utilizing fibroblasts isolated from the patients' rotator intervals, we analyzed their responses to profibrotic stimulation with transforming growth factor ß1 (TGFß1). We compared TGFß1-dependent changes in the production of procollagen I. We studied auxiliary proteins, prolyl 4-hydroxylase (P4H), and heat shock protein 47 (HSP47), that control procollagen stability and folding. A group of other proteins involved in excessive scar formation, including connective tissue growth factor (CTGF), α smooth muscle actin (αSMA), and fibronectin, was also analyzed. Results: We observed robust TGFß1-dependent increases in the production of CTGF, HSP47, αSMA, procollagen I, and fibronectin in fibroblasts from both groups of patients. In contrast, TGFß1-dependent P4H production increased only in the stiff-shoulder-derived fibroblasts. Conclusion: Results suggest P4H may serve as an element of a mechanism that modulates the fibrotic response after rotator cuff injury.

Evaluating the Efficacy of a Thermoresponsive Hydrogel for Delivering Anti-Collagen Antibodies to Reduce Posttraumatic Scarring in Orthopedic Tissues.

Excessive posttraumatic scarring in orthopedic tissues, such as joint capsules, ligaments, tendons, muscles, and peripheral nerves, presents a significant medical problem, resulting in pain, restricted joint mobility, and impaired musculoskeletal function. Current treatments for excessive scarring are often ineffective and require the surgical removal of fibrotic tissue, which can aggravate the problem. The primary component of orthopedic scars is collagen I-rich fibrils. Our research team has developed a monoclonal anti-collagen antibody (ACA) that alleviates posttraumatic scarring by inhibiting collagen fibril formation. We previously established the safety and efficacy of ACA in a rabbit-based arthrofibrosis model. In this study, we evaluate the utility of a well-characterized thermoresponsive hydrogel (THG) as a delivery vehicle for ACA to injury sites. Crucial components of the hydrogel included N-isopropylacrylamide, poly(ethylene glycol) diacrylate, and hyaluronic acid. Our investigation focused on in vitro ACA release kinetics, stability, and activity. Additionally, we examined the antigen-binding characteristics of ACA post-release from the THG in an in vivo context. Our preliminary findings suggest that the THG construct exhibits promise as a delivery platform for antibody-based therapeutics to reduce excessive scarring in orthopedic tissues.

Extracellular Targets to Reduce Excessive Scarring in Response to Tissue Injury.

Excessive scar formation is a hallmark of localized and systemic fibrotic disorders. Despite extensive studies to define valid anti-fibrotic targets and develop effective therapeutics, progressive fibrosis remains a significant medical problem. Regardless of the injury type or location of wounded tissue, excessive production and accumulation of collagen-rich extracellular matrix is the common denominator of all fibrotic disorders. A long-standing dogma was that anti-fibrotic approaches should focus on overall intracellular processes that drive fibrotic scarring. Because of the poor outcomes of these approaches, scientific efforts now focus on regulating the extracellular components of fibrotic tissues. Crucial extracellular players include cellular receptors of matrix components, macromolecules that form the matrix architecture, auxiliary proteins that facilitate the formation of stiff scar tissue, matricellular proteins, and extracellular vesicles that modulate matrix homeostasis. This review summarizes studies targeting the extracellular aspects of fibrotic tissue synthesis, presents the rationale for these studies, and discusses the progress and limitations of current extracellular approaches to limit fibrotic healing.

Visualizing molecular polar order in tissues via electromechanical coupling.

Electron microscopy (EM) and atomic force microscopy (AFM) techniques have long been used to characterize collagen fibril ordering and alignment in connective tissues. These techniques, however, are unable to map collagen fibril polarity, i.e., the polar orientation that is directed from the amine to the carboxyl termini. Using a voltage modulated AFM-based technique called piezoresponse force microscopy (PFM), we show it is possible to visualize both the alignment of collagen fibrils within a tissue and the polar orientation of the fibrils with minimal sample preparation. We demonstrate the technique on rat tail tendon and porcine eye tissues in ambient conditions. In each sample, fibrils are arranged into domains whereby neighboring domains exhibit opposite polarizations, which in some cases extend to the individual fibrillar level. Uniform polarity has not been observed in any of the tissues studied. Evidence of anti-parallel ordering of the amine to carboxyl polarity in bundles of fibrils or in individual fibrils is found in all tissues, which has relevance for understanding mechanical and biofunctional properties and the formation of connective tissues. The technique can be applied to any biological material containing piezoelectric biopolymers or polysaccharides.

Remodeling of the dermal-epidermal junction in bilayered skin constructs after silencing the expression of the p.R2622Q and p.G2623C collagen VII mutants.

The integrity of skin depends on a complex system of extracellular matrix molecules that form a biological scaffold. One of its elements is the dermal basement membrane that provides a link between the epidermis and the dermis. Mutations in collagen VII, a key component of the dermal membrane zone, are associated with dystrophic epidermolysis bullosa. Although it has been proposed that silencing the mutated COL7A1 allele is a promising approach to restore the dermal basement membrane zone formed in the presence of collagen VII mutants, limitations exist to testing this proposal. Here, we employed a model that utilized skin-like constructs in which engineered collagen VII mutant chains harboring the R2622Q or G2623C substitution were expressed conditionally, but the wild-type chains were expressed unconditionally. We demonstrated that switching off the production of the mutant collagen VII chains in skin constructs restores the organization of collagen VII and laminin 332 deposits in the dermal-epidermal junction to the level of control. We also demonstrated that remodeling of collagen IV deposits was not fully effective after silencing the expression of collagen VII mutants. Thus, our study suggests that while silencing mutant alleles of COL7A1 may repair critical elements of the affected dermal basement membrane, it may not be sufficient to fully remodel its entire architecture initially formed in the presence of the mutant collagen VII chains.

Circulating inflammatory cytokines alter transcriptional activity within fibrotic tissue of Dupuytren's disease patients.

Dupuytren's disease is a benign fibroproliferative disorder of the hand that results in disabling digital contractures that impair function and diminish the quality of life. The incidence of this disease has been correlated with chronic inflammatory states, but any direct association between inflammatory cytokines and Dupuytren's disease is not known. We hypothesized that advanced fibroproliferation is associated with increased levels of circulating inflammatory cytokines. Blood and fibrotic cord tissue were collected preoperatively from patients with severe contracture and control patients. Blood plasma concentrations of known inflammatory cytokines were evaluated using a multiplex immunoassay. Proteins from the cord tissue were analyzed by RNA sequencing and immunohistochemistry. Moreover, collagen-rich cords were analyzed using Fourier-transform infrared spectroscopy. The results indicate that patients exhibited significantly elevated circulating inflammatory cytokines, including tumor necrosis factor-α (TNF-α), interleukin (IL)-2, and IL-12p70, as compared with controls. Similarly, IL-4 and IL-13 were detected significantly more frequently in Dupuytren's disease as compared with control. RNA sequencing revealed 5311 differentially expressed genes and distinct clustering between diseased and control samples. In addition to increased expression of genes associated with fibroproliferation, we also observed upregulation of transcripts activated by inflammatory cytokines, including prolactin inducible protein and keratin intermediate filaments. IL-2, but not TNF-α, was detected in fibrotic cord tissue by immunohistochemistry. Finally, spectroscopic assays revealed a significant reduction of the collagen content and alterations of collagen cross-linking within the Dupuytren's disease tissues. In total, our results illustrate that patients with severe Dupuytren's disease exhibit substantially elevated circulating inflammatory cytokines that may drive fibroproliferation. Clinical Significance: The results from this study establish the basis for a specific cytokine profile that may be useful for diagnostic testing and therapeutic intervention in Dupuytren's disease.

Persistence of intracellular and extracellular changes after incompletely suppressing expression of the R789C (p.R989C) and R992C (p.R1192C) collagen II mutants.

Mutations in COL2A1 produce a spectrum of disorders whose hallmark feature is alterations in skeletal development. Attempts to counteract the effects of collagen mutations at the molecular level have been relatively ineffective due to the inability to selectively suppress a mutant allele, and failure to deliver a sufficient number of cells expressing wild-type collagen. Moreover, these approaches are hampered because the minimal therapeutic conditions that would allow extracellular matrix remodeling and recovery of cells from stress are not known. Here, we employed a tetracycline-inducible system for expressing the R789C or R992C collagen II mutants, allowing us to decrease the production of mutant proteins by 25, 50, 75, or 100% with respect to their initial production. Through analysis of intracellular and extracellular parameters we have shown that affected cell/matrix systems are able to recover from mutation-induced aberrations only when 100% expression of mutant collagens is shut off, but not if the expression of small amounts of mutant molecules persists in the system. Our data suggest that efficient remodeling of tissues affected by the presence of thermolabile collagen mutants may depend on their complete elimination rather than on partial reduction.

Recessive COL6A2 C-globular missense mutations in Ullrich congenital muscular dystrophy: role of the C2a splice variant.

Ullrich congenital muscular dystrophy (UCMD) is a disabling and life-threatening disorder resulting from either recessive or dominant mutations in genes encoding collagen VI. Although the majority of the recessive UCMD cases have frameshift or nonsense mutations in COL6A1, COL6A2, or COL6A3, recessive structural mutations in the COL6A2 C-globular region are emerging also. However, the underlying molecular mechanisms have remained elusive. Here we identified a homozygous COL6A2 E624K mutation (C1 subdomain) and a homozygous COL6A2 R876S mutation (C2 subdomain) in two UCMD patients. The consequences of the mutations were investigated using fibroblasts from patients and cells stably transfected with the mutant constructs. In contrast to expectations based on the clinical severity of these two patients, secretion and assembly of collagen VI were moderately affected by the E624K mutation but severely impaired by the R876S substitution. The E624K substitution altered the electrostatic potential of the region surrounding the metal ion-dependent adhesion site, resulting in a collagen VI network containing thick fibrils and spots with densely packed microfibrils. The R876S mutation prevented the chain from assembling into triple-helical collagen VI molecules. The minute amount of collagen VI secreted by the R876S fibroblasts was solely composed of a faster migrating chain corresponding to the C2a splice variant with an alternative C2 subdomain. In transfected cells, the C2a splice variant was able to assemble into short microfibrils. Together, the results suggest that the C2a splice variant may functionally compensate for the loss of the normal COL6A2 chain when mutations occur in the C2 subdomain.

Mechanisms of reducing joint stiffness by blocking collagen fibrillogenesis in a rabbit model of posttraumatic arthrofibrosis.

Posttraumatic fibrotic scarring is a significant medical problem that alters the proper functioning of injured tissues. Current methods to reduce posttraumatic fibrosis rely on anti-inflammatory and anti-proliferative agents with broad intracellular targets. As a result, their use is not fully effective and may cause unwanted side effects. Our group previously demonstrated that extracellular collagen fibrillogenesis is a valid and specific target to reduce collagen-rich scar buildup. Our previous studies showed that a rationally designed antibody that binds the C-terminal telopeptide of the α2(I) chain involved in the aggregation of collagen molecules limits fibril assembly in vitro and reduces scar formation in vivo. Here, we have utilized a clinically relevant arthrofibrosis model to study the broad mechanisms of the anti-scarring activity of this antibody. Moreover, we analyzed the effects of targeting collagen fibril formation on the quality of healed joint tissues, including the posterior capsule, patellar tendon, and subchondral bone. Our results show that blocking collagen fibrillogenesis not only reduces collagen content in the scar, but also accelerates the remodeling of healing tissues and changes the collagen fibrils' cross-linking. In total, this study demonstrated that targeting collagen fibrillogenesis to limit arthrofibrosis affects neither the quality of healing of the joint tissues nor disturbs vital tissues and organs.